a117a6d66e
3522 zfs module should not allow uninitialized variables Reviewed by: Sebastien Roy <seb@delphix.com> Reviewed by: Adam Leventhal <ahl@delphix.com> Reviewed by: Matthew Ahrens <mahrens@delphix.com> Approved by: Garrett D'Amore <garrett@damore.org> References: https://www.illumos.org/issues/3522 illumos/illumos-gate@d5285cae91 Ported-by: Richard Yao <ryao@gentoo.org> Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> Porting notes: 1. ZFSOnLinux had already addressed many of these issues because of its use of -Wall. However, the manner in which they were addressed differed. The illumos fixes replace the ones previously made in ZFSOnLinux to reduce code differences. 2. Part of the upstream patch made a small change to arc.c that might address zfsonlinux/zfs#1334. 3. The initialization of aclsize in zfs_log_create() differs because vsecp is a NULL pointer on ZFSOnLinux. 4. The changes to zfs_register_callbacks() were dropped because it has diverged and needs to be resynced.
2155 lines
60 KiB
C
2155 lines
60 KiB
C
/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License (the "License").
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* You may not use this file except in compliance with the License.
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*
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* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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* or http://www.opensolaris.org/os/licensing.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information: Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*/
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/*
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* Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
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* Copyright (c) 2012 by Delphix. All rights reserved.
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*/
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#include <sys/zfs_context.h>
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#include <sys/spa.h>
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#include <sys/vdev_impl.h>
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#include <sys/zio.h>
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#include <sys/zio_checksum.h>
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#include <sys/fs/zfs.h>
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#include <sys/fm/fs/zfs.h>
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/*
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* Virtual device vector for RAID-Z.
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*
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* This vdev supports single, double, and triple parity. For single parity,
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* we use a simple XOR of all the data columns. For double or triple parity,
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* we use a special case of Reed-Solomon coding. This extends the
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* technique described in "The mathematics of RAID-6" by H. Peter Anvin by
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* drawing on the system described in "A Tutorial on Reed-Solomon Coding for
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* Fault-Tolerance in RAID-like Systems" by James S. Plank on which the
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* former is also based. The latter is designed to provide higher performance
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* for writes.
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*
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* Note that the Plank paper claimed to support arbitrary N+M, but was then
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* amended six years later identifying a critical flaw that invalidates its
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* claims. Nevertheless, the technique can be adapted to work for up to
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* triple parity. For additional parity, the amendment "Note: Correction to
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* the 1997 Tutorial on Reed-Solomon Coding" by James S. Plank and Ying Ding
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* is viable, but the additional complexity means that write performance will
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* suffer.
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*
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* All of the methods above operate on a Galois field, defined over the
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* integers mod 2^N. In our case we choose N=8 for GF(8) so that all elements
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* can be expressed with a single byte. Briefly, the operations on the
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* field are defined as follows:
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*
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* o addition (+) is represented by a bitwise XOR
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* o subtraction (-) is therefore identical to addition: A + B = A - B
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* o multiplication of A by 2 is defined by the following bitwise expression:
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* (A * 2)_7 = A_6
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* (A * 2)_6 = A_5
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* (A * 2)_5 = A_4
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* (A * 2)_4 = A_3 + A_7
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* (A * 2)_3 = A_2 + A_7
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* (A * 2)_2 = A_1 + A_7
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* (A * 2)_1 = A_0
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* (A * 2)_0 = A_7
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*
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* In C, multiplying by 2 is therefore ((a << 1) ^ ((a & 0x80) ? 0x1d : 0)).
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* As an aside, this multiplication is derived from the error correcting
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* primitive polynomial x^8 + x^4 + x^3 + x^2 + 1.
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*
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* Observe that any number in the field (except for 0) can be expressed as a
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* power of 2 -- a generator for the field. We store a table of the powers of
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* 2 and logs base 2 for quick look ups, and exploit the fact that A * B can
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* be rewritten as 2^(log_2(A) + log_2(B)) (where '+' is normal addition rather
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* than field addition). The inverse of a field element A (A^-1) is therefore
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* A ^ (255 - 1) = A^254.
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*
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* The up-to-three parity columns, P, Q, R over several data columns,
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* D_0, ... D_n-1, can be expressed by field operations:
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*
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* P = D_0 + D_1 + ... + D_n-2 + D_n-1
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* Q = 2^n-1 * D_0 + 2^n-2 * D_1 + ... + 2^1 * D_n-2 + 2^0 * D_n-1
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* = ((...((D_0) * 2 + D_1) * 2 + ...) * 2 + D_n-2) * 2 + D_n-1
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* R = 4^n-1 * D_0 + 4^n-2 * D_1 + ... + 4^1 * D_n-2 + 4^0 * D_n-1
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* = ((...((D_0) * 4 + D_1) * 4 + ...) * 4 + D_n-2) * 4 + D_n-1
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*
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* We chose 1, 2, and 4 as our generators because 1 corresponds to the trival
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* XOR operation, and 2 and 4 can be computed quickly and generate linearly-
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* independent coefficients. (There are no additional coefficients that have
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* this property which is why the uncorrected Plank method breaks down.)
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*
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* See the reconstruction code below for how P, Q and R can used individually
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* or in concert to recover missing data columns.
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*/
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typedef struct raidz_col {
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uint64_t rc_devidx; /* child device index for I/O */
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uint64_t rc_offset; /* device offset */
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uint64_t rc_size; /* I/O size */
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void *rc_data; /* I/O data */
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void *rc_gdata; /* used to store the "good" version */
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int rc_error; /* I/O error for this device */
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uint8_t rc_tried; /* Did we attempt this I/O column? */
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uint8_t rc_skipped; /* Did we skip this I/O column? */
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} raidz_col_t;
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typedef struct raidz_map {
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uint64_t rm_cols; /* Regular column count */
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uint64_t rm_scols; /* Count including skipped columns */
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uint64_t rm_bigcols; /* Number of oversized columns */
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uint64_t rm_asize; /* Actual total I/O size */
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uint64_t rm_missingdata; /* Count of missing data devices */
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uint64_t rm_missingparity; /* Count of missing parity devices */
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uint64_t rm_firstdatacol; /* First data column/parity count */
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uint64_t rm_nskip; /* Skipped sectors for padding */
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uint64_t rm_skipstart; /* Column index of padding start */
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void *rm_datacopy; /* rm_asize-buffer of copied data */
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uintptr_t rm_reports; /* # of referencing checksum reports */
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uint8_t rm_freed; /* map no longer has referencing ZIO */
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uint8_t rm_ecksuminjected; /* checksum error was injected */
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raidz_col_t rm_col[1]; /* Flexible array of I/O columns */
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} raidz_map_t;
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#define VDEV_RAIDZ_P 0
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#define VDEV_RAIDZ_Q 1
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#define VDEV_RAIDZ_R 2
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#define VDEV_RAIDZ_MUL_2(x) (((x) << 1) ^ (((x) & 0x80) ? 0x1d : 0))
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#define VDEV_RAIDZ_MUL_4(x) (VDEV_RAIDZ_MUL_2(VDEV_RAIDZ_MUL_2(x)))
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/*
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* We provide a mechanism to perform the field multiplication operation on a
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* 64-bit value all at once rather than a byte at a time. This works by
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* creating a mask from the top bit in each byte and using that to
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* conditionally apply the XOR of 0x1d.
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*/
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#define VDEV_RAIDZ_64MUL_2(x, mask) \
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{ \
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(mask) = (x) & 0x8080808080808080ULL; \
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(mask) = ((mask) << 1) - ((mask) >> 7); \
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(x) = (((x) << 1) & 0xfefefefefefefefeULL) ^ \
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((mask) & 0x1d1d1d1d1d1d1d1dULL); \
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}
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#define VDEV_RAIDZ_64MUL_4(x, mask) \
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{ \
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VDEV_RAIDZ_64MUL_2((x), mask); \
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VDEV_RAIDZ_64MUL_2((x), mask); \
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}
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/*
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* Force reconstruction to use the general purpose method.
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*/
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int vdev_raidz_default_to_general;
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/*
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* These two tables represent powers and logs of 2 in the Galois field defined
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* above. These values were computed by repeatedly multiplying by 2 as above.
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*/
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static const uint8_t vdev_raidz_pow2[256] = {
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0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80,
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0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26,
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0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9,
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0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0,
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0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35,
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0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23,
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0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0,
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0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1,
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0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc,
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0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0,
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0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f,
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0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2,
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0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88,
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0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce,
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0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93,
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0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc,
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0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9,
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0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54,
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0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa,
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0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73,
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0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e,
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0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff,
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0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4,
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0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41,
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0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e,
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0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6,
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0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef,
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0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09,
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0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5,
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0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16,
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0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83,
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0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x01
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};
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static const uint8_t vdev_raidz_log2[256] = {
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0x00, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6,
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0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b,
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0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81,
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0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71,
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0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21,
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0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45,
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0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9,
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0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6,
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0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd,
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0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88,
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0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd,
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0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40,
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0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e,
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0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d,
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0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b,
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0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57,
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0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d,
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0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18,
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0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c,
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0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e,
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0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd,
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0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61,
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0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e,
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0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2,
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0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76,
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0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6,
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0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa,
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0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a,
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0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51,
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0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7,
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0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8,
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0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf,
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};
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static void vdev_raidz_generate_parity(raidz_map_t *rm);
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/*
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* Multiply a given number by 2 raised to the given power.
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*/
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static uint8_t
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vdev_raidz_exp2(uint_t a, int exp)
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{
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if (a == 0)
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return (0);
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ASSERT(exp >= 0);
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ASSERT(vdev_raidz_log2[a] > 0 || a == 1);
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exp += vdev_raidz_log2[a];
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if (exp > 255)
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exp -= 255;
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return (vdev_raidz_pow2[exp]);
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}
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static void
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vdev_raidz_map_free(raidz_map_t *rm)
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{
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int c;
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size_t size;
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for (c = 0; c < rm->rm_firstdatacol; c++) {
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zio_buf_free(rm->rm_col[c].rc_data, rm->rm_col[c].rc_size);
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if (rm->rm_col[c].rc_gdata != NULL)
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zio_buf_free(rm->rm_col[c].rc_gdata,
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rm->rm_col[c].rc_size);
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}
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size = 0;
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for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++)
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size += rm->rm_col[c].rc_size;
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if (rm->rm_datacopy != NULL)
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zio_buf_free(rm->rm_datacopy, size);
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kmem_free(rm, offsetof(raidz_map_t, rm_col[rm->rm_scols]));
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}
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static void
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vdev_raidz_map_free_vsd(zio_t *zio)
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{
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raidz_map_t *rm = zio->io_vsd;
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ASSERT0(rm->rm_freed);
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rm->rm_freed = 1;
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if (rm->rm_reports == 0)
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vdev_raidz_map_free(rm);
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}
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/*ARGSUSED*/
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static void
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vdev_raidz_cksum_free(void *arg, size_t ignored)
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{
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raidz_map_t *rm = arg;
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ASSERT3U(rm->rm_reports, >, 0);
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if (--rm->rm_reports == 0 && rm->rm_freed != 0)
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vdev_raidz_map_free(rm);
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}
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static void
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vdev_raidz_cksum_finish(zio_cksum_report_t *zcr, const void *good_data)
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{
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raidz_map_t *rm = zcr->zcr_cbdata;
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size_t c = zcr->zcr_cbinfo;
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size_t x;
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const char *good = NULL;
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const char *bad = rm->rm_col[c].rc_data;
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if (good_data == NULL) {
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zfs_ereport_finish_checksum(zcr, NULL, NULL, B_FALSE);
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return;
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}
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|
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if (c < rm->rm_firstdatacol) {
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/*
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* The first time through, calculate the parity blocks for
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* the good data (this relies on the fact that the good
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* data never changes for a given logical ZIO)
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*/
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if (rm->rm_col[0].rc_gdata == NULL) {
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char *bad_parity[VDEV_RAIDZ_MAXPARITY];
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char *buf;
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/*
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* Set up the rm_col[]s to generate the parity for
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* good_data, first saving the parity bufs and
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* replacing them with buffers to hold the result.
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*/
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for (x = 0; x < rm->rm_firstdatacol; x++) {
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bad_parity[x] = rm->rm_col[x].rc_data;
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rm->rm_col[x].rc_data = rm->rm_col[x].rc_gdata =
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zio_buf_alloc(rm->rm_col[x].rc_size);
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}
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/* fill in the data columns from good_data */
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buf = (char *)good_data;
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for (; x < rm->rm_cols; x++) {
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rm->rm_col[x].rc_data = buf;
|
|
buf += rm->rm_col[x].rc_size;
|
|
}
|
|
|
|
/*
|
|
* Construct the parity from the good data.
|
|
*/
|
|
vdev_raidz_generate_parity(rm);
|
|
|
|
/* restore everything back to its original state */
|
|
for (x = 0; x < rm->rm_firstdatacol; x++)
|
|
rm->rm_col[x].rc_data = bad_parity[x];
|
|
|
|
buf = rm->rm_datacopy;
|
|
for (x = rm->rm_firstdatacol; x < rm->rm_cols; x++) {
|
|
rm->rm_col[x].rc_data = buf;
|
|
buf += rm->rm_col[x].rc_size;
|
|
}
|
|
}
|
|
|
|
ASSERT3P(rm->rm_col[c].rc_gdata, !=, NULL);
|
|
good = rm->rm_col[c].rc_gdata;
|
|
} else {
|
|
/* adjust good_data to point at the start of our column */
|
|
good = good_data;
|
|
|
|
for (x = rm->rm_firstdatacol; x < c; x++)
|
|
good += rm->rm_col[x].rc_size;
|
|
}
|
|
|
|
/* we drop the ereport if it ends up that the data was good */
|
|
zfs_ereport_finish_checksum(zcr, good, bad, B_TRUE);
|
|
}
|
|
|
|
/*
|
|
* 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_raidz_cksum_finish() time we can compare it with the good data.
|
|
*/
|
|
static void
|
|
vdev_raidz_cksum_report(zio_t *zio, zio_cksum_report_t *zcr, void *arg)
|
|
{
|
|
size_t c = (size_t)(uintptr_t)arg;
|
|
caddr_t buf;
|
|
|
|
raidz_map_t *rm = zio->io_vsd;
|
|
size_t size;
|
|
|
|
/* set up the report and bump the refcount */
|
|
zcr->zcr_cbdata = rm;
|
|
zcr->zcr_cbinfo = c;
|
|
zcr->zcr_finish = vdev_raidz_cksum_finish;
|
|
zcr->zcr_free = vdev_raidz_cksum_free;
|
|
|
|
rm->rm_reports++;
|
|
ASSERT3U(rm->rm_reports, >, 0);
|
|
|
|
if (rm->rm_datacopy != 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.
|
|
*/
|
|
|
|
size = 0;
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++)
|
|
size += rm->rm_col[c].rc_size;
|
|
|
|
buf = rm->rm_datacopy = zio_buf_alloc(size);
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
raidz_col_t *col = &rm->rm_col[c];
|
|
|
|
bcopy(col->rc_data, buf, col->rc_size);
|
|
col->rc_data = buf;
|
|
|
|
buf += col->rc_size;
|
|
}
|
|
ASSERT3P(buf - (caddr_t)rm->rm_datacopy, ==, size);
|
|
}
|
|
|
|
static const zio_vsd_ops_t vdev_raidz_vsd_ops = {
|
|
vdev_raidz_map_free_vsd,
|
|
vdev_raidz_cksum_report
|
|
};
|
|
|
|
static raidz_map_t *
|
|
vdev_raidz_map_alloc(zio_t *zio, uint64_t unit_shift, uint64_t dcols,
|
|
uint64_t nparity)
|
|
{
|
|
raidz_map_t *rm;
|
|
uint64_t b = zio->io_offset >> unit_shift;
|
|
uint64_t s = zio->io_size >> unit_shift;
|
|
uint64_t f = b % dcols;
|
|
uint64_t o = (b / dcols) << unit_shift;
|
|
uint64_t q, r, c, bc, col, acols, scols, coff, devidx, asize, tot;
|
|
|
|
q = s / (dcols - nparity);
|
|
r = s - q * (dcols - nparity);
|
|
bc = (r == 0 ? 0 : r + nparity);
|
|
tot = s + nparity * (q + (r == 0 ? 0 : 1));
|
|
|
|
if (q == 0) {
|
|
acols = bc;
|
|
scols = MIN(dcols, roundup(bc, nparity + 1));
|
|
} else {
|
|
acols = dcols;
|
|
scols = dcols;
|
|
}
|
|
|
|
ASSERT3U(acols, <=, scols);
|
|
|
|
rm = kmem_alloc(offsetof(raidz_map_t, rm_col[scols]), KM_PUSHPAGE);
|
|
|
|
rm->rm_cols = acols;
|
|
rm->rm_scols = scols;
|
|
rm->rm_bigcols = bc;
|
|
rm->rm_skipstart = bc;
|
|
rm->rm_missingdata = 0;
|
|
rm->rm_missingparity = 0;
|
|
rm->rm_firstdatacol = nparity;
|
|
rm->rm_datacopy = NULL;
|
|
rm->rm_reports = 0;
|
|
rm->rm_freed = 0;
|
|
rm->rm_ecksuminjected = 0;
|
|
|
|
asize = 0;
|
|
|
|
for (c = 0; c < scols; c++) {
|
|
col = f + c;
|
|
coff = o;
|
|
if (col >= dcols) {
|
|
col -= dcols;
|
|
coff += 1ULL << unit_shift;
|
|
}
|
|
rm->rm_col[c].rc_devidx = col;
|
|
rm->rm_col[c].rc_offset = coff;
|
|
rm->rm_col[c].rc_data = NULL;
|
|
rm->rm_col[c].rc_gdata = NULL;
|
|
rm->rm_col[c].rc_error = 0;
|
|
rm->rm_col[c].rc_tried = 0;
|
|
rm->rm_col[c].rc_skipped = 0;
|
|
|
|
if (c >= acols)
|
|
rm->rm_col[c].rc_size = 0;
|
|
else if (c < bc)
|
|
rm->rm_col[c].rc_size = (q + 1) << unit_shift;
|
|
else
|
|
rm->rm_col[c].rc_size = q << unit_shift;
|
|
|
|
asize += rm->rm_col[c].rc_size;
|
|
}
|
|
|
|
ASSERT3U(asize, ==, tot << unit_shift);
|
|
rm->rm_asize = roundup(asize, (nparity + 1) << unit_shift);
|
|
rm->rm_nskip = roundup(tot, nparity + 1) - tot;
|
|
ASSERT3U(rm->rm_asize - asize, ==, rm->rm_nskip << unit_shift);
|
|
ASSERT3U(rm->rm_nskip, <=, nparity);
|
|
|
|
for (c = 0; c < rm->rm_firstdatacol; c++)
|
|
rm->rm_col[c].rc_data = zio_buf_alloc(rm->rm_col[c].rc_size);
|
|
|
|
rm->rm_col[c].rc_data = zio->io_data;
|
|
|
|
for (c = c + 1; c < acols; c++)
|
|
rm->rm_col[c].rc_data = (char *)rm->rm_col[c - 1].rc_data +
|
|
rm->rm_col[c - 1].rc_size;
|
|
|
|
/*
|
|
* If all data stored spans all columns, there's a danger that parity
|
|
* will always be on the same device and, since parity isn't read
|
|
* during normal operation, that that device's I/O bandwidth won't be
|
|
* used effectively. We therefore switch the parity every 1MB.
|
|
*
|
|
* ... at least that was, ostensibly, the theory. As a practical
|
|
* matter unless we juggle the parity between all devices evenly, we
|
|
* won't see any benefit. Further, occasional writes that aren't a
|
|
* multiple of the LCM of the number of children and the minimum
|
|
* stripe width are sufficient to avoid pessimal behavior.
|
|
* Unfortunately, this decision created an implicit on-disk format
|
|
* requirement that we need to support for all eternity, but only
|
|
* for single-parity RAID-Z.
|
|
*
|
|
* If we intend to skip a sector in the zeroth column for padding
|
|
* we must make sure to note this swap. We will never intend to
|
|
* skip the first column since at least one data and one parity
|
|
* column must appear in each row.
|
|
*/
|
|
ASSERT(rm->rm_cols >= 2);
|
|
ASSERT(rm->rm_col[0].rc_size == rm->rm_col[1].rc_size);
|
|
|
|
if (rm->rm_firstdatacol == 1 && (zio->io_offset & (1ULL << 20))) {
|
|
devidx = rm->rm_col[0].rc_devidx;
|
|
o = rm->rm_col[0].rc_offset;
|
|
rm->rm_col[0].rc_devidx = rm->rm_col[1].rc_devidx;
|
|
rm->rm_col[0].rc_offset = rm->rm_col[1].rc_offset;
|
|
rm->rm_col[1].rc_devidx = devidx;
|
|
rm->rm_col[1].rc_offset = o;
|
|
|
|
if (rm->rm_skipstart == 0)
|
|
rm->rm_skipstart = 1;
|
|
}
|
|
|
|
zio->io_vsd = rm;
|
|
zio->io_vsd_ops = &vdev_raidz_vsd_ops;
|
|
return (rm);
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_generate_parity_p(raidz_map_t *rm)
|
|
{
|
|
uint64_t *p, *src, pcount, ccount, i;
|
|
int c;
|
|
|
|
pcount = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]);
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
src = rm->rm_col[c].rc_data;
|
|
p = rm->rm_col[VDEV_RAIDZ_P].rc_data;
|
|
ccount = rm->rm_col[c].rc_size / sizeof (src[0]);
|
|
|
|
if (c == rm->rm_firstdatacol) {
|
|
ASSERT(ccount == pcount);
|
|
for (i = 0; i < ccount; i++, src++, p++) {
|
|
*p = *src;
|
|
}
|
|
} else {
|
|
ASSERT(ccount <= pcount);
|
|
for (i = 0; i < ccount; i++, src++, p++) {
|
|
*p ^= *src;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_generate_parity_pq(raidz_map_t *rm)
|
|
{
|
|
uint64_t *p, *q, *src, pcnt, ccnt, mask, i;
|
|
int c;
|
|
|
|
pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]);
|
|
ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size ==
|
|
rm->rm_col[VDEV_RAIDZ_Q].rc_size);
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
src = rm->rm_col[c].rc_data;
|
|
p = rm->rm_col[VDEV_RAIDZ_P].rc_data;
|
|
q = rm->rm_col[VDEV_RAIDZ_Q].rc_data;
|
|
|
|
ccnt = rm->rm_col[c].rc_size / sizeof (src[0]);
|
|
|
|
if (c == rm->rm_firstdatacol) {
|
|
ASSERT(ccnt == pcnt || ccnt == 0);
|
|
for (i = 0; i < ccnt; i++, src++, p++, q++) {
|
|
*p = *src;
|
|
*q = *src;
|
|
}
|
|
for (; i < pcnt; i++, src++, p++, q++) {
|
|
*p = 0;
|
|
*q = 0;
|
|
}
|
|
} else {
|
|
ASSERT(ccnt <= pcnt);
|
|
|
|
/*
|
|
* Apply the algorithm described above by multiplying
|
|
* the previous result and adding in the new value.
|
|
*/
|
|
for (i = 0; i < ccnt; i++, src++, p++, q++) {
|
|
*p ^= *src;
|
|
|
|
VDEV_RAIDZ_64MUL_2(*q, mask);
|
|
*q ^= *src;
|
|
}
|
|
|
|
/*
|
|
* Treat short columns as though they are full of 0s.
|
|
* Note that there's therefore nothing needed for P.
|
|
*/
|
|
for (; i < pcnt; i++, q++) {
|
|
VDEV_RAIDZ_64MUL_2(*q, mask);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_generate_parity_pqr(raidz_map_t *rm)
|
|
{
|
|
uint64_t *p, *q, *r, *src, pcnt, ccnt, mask, i;
|
|
int c;
|
|
|
|
pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]);
|
|
ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size ==
|
|
rm->rm_col[VDEV_RAIDZ_Q].rc_size);
|
|
ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size ==
|
|
rm->rm_col[VDEV_RAIDZ_R].rc_size);
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
src = rm->rm_col[c].rc_data;
|
|
p = rm->rm_col[VDEV_RAIDZ_P].rc_data;
|
|
q = rm->rm_col[VDEV_RAIDZ_Q].rc_data;
|
|
r = rm->rm_col[VDEV_RAIDZ_R].rc_data;
|
|
|
|
ccnt = rm->rm_col[c].rc_size / sizeof (src[0]);
|
|
|
|
if (c == rm->rm_firstdatacol) {
|
|
ASSERT(ccnt == pcnt || ccnt == 0);
|
|
for (i = 0; i < ccnt; i++, src++, p++, q++, r++) {
|
|
*p = *src;
|
|
*q = *src;
|
|
*r = *src;
|
|
}
|
|
for (; i < pcnt; i++, src++, p++, q++, r++) {
|
|
*p = 0;
|
|
*q = 0;
|
|
*r = 0;
|
|
}
|
|
} else {
|
|
ASSERT(ccnt <= pcnt);
|
|
|
|
/*
|
|
* Apply the algorithm described above by multiplying
|
|
* the previous result and adding in the new value.
|
|
*/
|
|
for (i = 0; i < ccnt; i++, src++, p++, q++, r++) {
|
|
*p ^= *src;
|
|
|
|
VDEV_RAIDZ_64MUL_2(*q, mask);
|
|
*q ^= *src;
|
|
|
|
VDEV_RAIDZ_64MUL_4(*r, mask);
|
|
*r ^= *src;
|
|
}
|
|
|
|
/*
|
|
* Treat short columns as though they are full of 0s.
|
|
* Note that there's therefore nothing needed for P.
|
|
*/
|
|
for (; i < pcnt; i++, q++, r++) {
|
|
VDEV_RAIDZ_64MUL_2(*q, mask);
|
|
VDEV_RAIDZ_64MUL_4(*r, mask);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Generate RAID parity in the first virtual columns according to the number of
|
|
* parity columns available.
|
|
*/
|
|
static void
|
|
vdev_raidz_generate_parity(raidz_map_t *rm)
|
|
{
|
|
switch (rm->rm_firstdatacol) {
|
|
case 1:
|
|
vdev_raidz_generate_parity_p(rm);
|
|
break;
|
|
case 2:
|
|
vdev_raidz_generate_parity_pq(rm);
|
|
break;
|
|
case 3:
|
|
vdev_raidz_generate_parity_pqr(rm);
|
|
break;
|
|
default:
|
|
cmn_err(CE_PANIC, "invalid RAID-Z configuration");
|
|
}
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_reconstruct_p(raidz_map_t *rm, int *tgts, int ntgts)
|
|
{
|
|
uint64_t *dst, *src, xcount, ccount, count, i;
|
|
int x = tgts[0];
|
|
int c;
|
|
|
|
ASSERT(ntgts == 1);
|
|
ASSERT(x >= rm->rm_firstdatacol);
|
|
ASSERT(x < rm->rm_cols);
|
|
|
|
xcount = rm->rm_col[x].rc_size / sizeof (src[0]);
|
|
ASSERT(xcount <= rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]));
|
|
ASSERT(xcount > 0);
|
|
|
|
src = rm->rm_col[VDEV_RAIDZ_P].rc_data;
|
|
dst = rm->rm_col[x].rc_data;
|
|
for (i = 0; i < xcount; i++, dst++, src++) {
|
|
*dst = *src;
|
|
}
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
src = rm->rm_col[c].rc_data;
|
|
dst = rm->rm_col[x].rc_data;
|
|
|
|
if (c == x)
|
|
continue;
|
|
|
|
ccount = rm->rm_col[c].rc_size / sizeof (src[0]);
|
|
count = MIN(ccount, xcount);
|
|
|
|
for (i = 0; i < count; i++, dst++, src++) {
|
|
*dst ^= *src;
|
|
}
|
|
}
|
|
|
|
return (1 << VDEV_RAIDZ_P);
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_reconstruct_q(raidz_map_t *rm, int *tgts, int ntgts)
|
|
{
|
|
uint64_t *dst, *src, xcount, ccount, count, mask, i;
|
|
uint8_t *b;
|
|
int x = tgts[0];
|
|
int c, j, exp;
|
|
|
|
ASSERT(ntgts == 1);
|
|
|
|
xcount = rm->rm_col[x].rc_size / sizeof (src[0]);
|
|
ASSERT(xcount <= rm->rm_col[VDEV_RAIDZ_Q].rc_size / sizeof (src[0]));
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
src = rm->rm_col[c].rc_data;
|
|
dst = rm->rm_col[x].rc_data;
|
|
|
|
if (c == x)
|
|
ccount = 0;
|
|
else
|
|
ccount = rm->rm_col[c].rc_size / sizeof (src[0]);
|
|
|
|
count = MIN(ccount, xcount);
|
|
|
|
if (c == rm->rm_firstdatacol) {
|
|
for (i = 0; i < count; i++, dst++, src++) {
|
|
*dst = *src;
|
|
}
|
|
for (; i < xcount; i++, dst++) {
|
|
*dst = 0;
|
|
}
|
|
|
|
} else {
|
|
for (i = 0; i < count; i++, dst++, src++) {
|
|
VDEV_RAIDZ_64MUL_2(*dst, mask);
|
|
*dst ^= *src;
|
|
}
|
|
|
|
for (; i < xcount; i++, dst++) {
|
|
VDEV_RAIDZ_64MUL_2(*dst, mask);
|
|
}
|
|
}
|
|
}
|
|
|
|
src = rm->rm_col[VDEV_RAIDZ_Q].rc_data;
|
|
dst = rm->rm_col[x].rc_data;
|
|
exp = 255 - (rm->rm_cols - 1 - x);
|
|
|
|
for (i = 0; i < xcount; i++, dst++, src++) {
|
|
*dst ^= *src;
|
|
for (j = 0, b = (uint8_t *)dst; j < 8; j++, b++) {
|
|
*b = vdev_raidz_exp2(*b, exp);
|
|
}
|
|
}
|
|
|
|
return (1 << VDEV_RAIDZ_Q);
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_reconstruct_pq(raidz_map_t *rm, int *tgts, int ntgts)
|
|
{
|
|
uint8_t *p, *q, *pxy, *qxy, *xd, *yd, tmp, a, b, aexp, bexp;
|
|
void *pdata, *qdata;
|
|
uint64_t xsize, ysize, i;
|
|
int x = tgts[0];
|
|
int y = tgts[1];
|
|
|
|
ASSERT(ntgts == 2);
|
|
ASSERT(x < y);
|
|
ASSERT(x >= rm->rm_firstdatacol);
|
|
ASSERT(y < rm->rm_cols);
|
|
|
|
ASSERT(rm->rm_col[x].rc_size >= rm->rm_col[y].rc_size);
|
|
|
|
/*
|
|
* Move the parity data aside -- we're going to compute parity as
|
|
* though columns x and y were full of zeros -- Pxy and Qxy. We want to
|
|
* reuse the parity generation mechanism without trashing the actual
|
|
* parity so we make those columns appear to be full of zeros by
|
|
* setting their lengths to zero.
|
|
*/
|
|
pdata = rm->rm_col[VDEV_RAIDZ_P].rc_data;
|
|
qdata = rm->rm_col[VDEV_RAIDZ_Q].rc_data;
|
|
xsize = rm->rm_col[x].rc_size;
|
|
ysize = rm->rm_col[y].rc_size;
|
|
|
|
rm->rm_col[VDEV_RAIDZ_P].rc_data =
|
|
zio_buf_alloc(rm->rm_col[VDEV_RAIDZ_P].rc_size);
|
|
rm->rm_col[VDEV_RAIDZ_Q].rc_data =
|
|
zio_buf_alloc(rm->rm_col[VDEV_RAIDZ_Q].rc_size);
|
|
rm->rm_col[x].rc_size = 0;
|
|
rm->rm_col[y].rc_size = 0;
|
|
|
|
vdev_raidz_generate_parity_pq(rm);
|
|
|
|
rm->rm_col[x].rc_size = xsize;
|
|
rm->rm_col[y].rc_size = ysize;
|
|
|
|
p = pdata;
|
|
q = qdata;
|
|
pxy = rm->rm_col[VDEV_RAIDZ_P].rc_data;
|
|
qxy = rm->rm_col[VDEV_RAIDZ_Q].rc_data;
|
|
xd = rm->rm_col[x].rc_data;
|
|
yd = rm->rm_col[y].rc_data;
|
|
|
|
/*
|
|
* We now have:
|
|
* Pxy = P + D_x + D_y
|
|
* Qxy = Q + 2^(ndevs - 1 - x) * D_x + 2^(ndevs - 1 - y) * D_y
|
|
*
|
|
* We can then solve for D_x:
|
|
* D_x = A * (P + Pxy) + B * (Q + Qxy)
|
|
* where
|
|
* A = 2^(x - y) * (2^(x - y) + 1)^-1
|
|
* B = 2^(ndevs - 1 - x) * (2^(x - y) + 1)^-1
|
|
*
|
|
* With D_x in hand, we can easily solve for D_y:
|
|
* D_y = P + Pxy + D_x
|
|
*/
|
|
|
|
a = vdev_raidz_pow2[255 + x - y];
|
|
b = vdev_raidz_pow2[255 - (rm->rm_cols - 1 - x)];
|
|
tmp = 255 - vdev_raidz_log2[a ^ 1];
|
|
|
|
aexp = vdev_raidz_log2[vdev_raidz_exp2(a, tmp)];
|
|
bexp = vdev_raidz_log2[vdev_raidz_exp2(b, tmp)];
|
|
|
|
for (i = 0; i < xsize; i++, p++, q++, pxy++, qxy++, xd++, yd++) {
|
|
*xd = vdev_raidz_exp2(*p ^ *pxy, aexp) ^
|
|
vdev_raidz_exp2(*q ^ *qxy, bexp);
|
|
|
|
if (i < ysize)
|
|
*yd = *p ^ *pxy ^ *xd;
|
|
}
|
|
|
|
zio_buf_free(rm->rm_col[VDEV_RAIDZ_P].rc_data,
|
|
rm->rm_col[VDEV_RAIDZ_P].rc_size);
|
|
zio_buf_free(rm->rm_col[VDEV_RAIDZ_Q].rc_data,
|
|
rm->rm_col[VDEV_RAIDZ_Q].rc_size);
|
|
|
|
/*
|
|
* Restore the saved parity data.
|
|
*/
|
|
rm->rm_col[VDEV_RAIDZ_P].rc_data = pdata;
|
|
rm->rm_col[VDEV_RAIDZ_Q].rc_data = qdata;
|
|
|
|
return ((1 << VDEV_RAIDZ_P) | (1 << VDEV_RAIDZ_Q));
|
|
}
|
|
|
|
/* BEGIN CSTYLED */
|
|
/*
|
|
* In the general case of reconstruction, we must solve the system of linear
|
|
* equations defined by the coeffecients used to generate parity as well as
|
|
* the contents of the data and parity disks. This can be expressed with
|
|
* vectors for the original data (D) and the actual data (d) and parity (p)
|
|
* and a matrix composed of the identity matrix (I) and a dispersal matrix (V):
|
|
*
|
|
* __ __ __ __
|
|
* | | __ __ | p_0 |
|
|
* | V | | D_0 | | p_m-1 |
|
|
* | | x | : | = | d_0 |
|
|
* | I | | D_n-1 | | : |
|
|
* | | ~~ ~~ | d_n-1 |
|
|
* ~~ ~~ ~~ ~~
|
|
*
|
|
* I is simply a square identity matrix of size n, and V is a vandermonde
|
|
* matrix defined by the coeffecients we chose for the various parity columns
|
|
* (1, 2, 4). Note that these values were chosen both for simplicity, speedy
|
|
* computation as well as linear separability.
|
|
*
|
|
* __ __ __ __
|
|
* | 1 .. 1 1 1 | | p_0 |
|
|
* | 2^n-1 .. 4 2 1 | __ __ | : |
|
|
* | 4^n-1 .. 16 4 1 | | D_0 | | p_m-1 |
|
|
* | 1 .. 0 0 0 | | D_1 | | d_0 |
|
|
* | 0 .. 0 0 0 | x | D_2 | = | d_1 |
|
|
* | : : : : | | : | | d_2 |
|
|
* | 0 .. 1 0 0 | | D_n-1 | | : |
|
|
* | 0 .. 0 1 0 | ~~ ~~ | : |
|
|
* | 0 .. 0 0 1 | | d_n-1 |
|
|
* ~~ ~~ ~~ ~~
|
|
*
|
|
* Note that I, V, d, and p are known. To compute D, we must invert the
|
|
* matrix and use the known data and parity values to reconstruct the unknown
|
|
* data values. We begin by removing the rows in V|I and d|p that correspond
|
|
* to failed or missing columns; we then make V|I square (n x n) and d|p
|
|
* sized n by removing rows corresponding to unused parity from the bottom up
|
|
* to generate (V|I)' and (d|p)'. We can then generate the inverse of (V|I)'
|
|
* using Gauss-Jordan elimination. In the example below we use m=3 parity
|
|
* columns, n=8 data columns, with errors in d_1, d_2, and p_1:
|
|
* __ __
|
|
* | 1 1 1 1 1 1 1 1 |
|
|
* | 128 64 32 16 8 4 2 1 | <-----+-+-- missing disks
|
|
* | 19 205 116 29 64 16 4 1 | / /
|
|
* | 1 0 0 0 0 0 0 0 | / /
|
|
* | 0 1 0 0 0 0 0 0 | <--' /
|
|
* (V|I) = | 0 0 1 0 0 0 0 0 | <---'
|
|
* | 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 1 1 1 1 1 1 1 1 |
|
|
* | 128 64 32 16 8 4 2 1 |
|
|
* | 19 205 116 29 64 16 4 1 |
|
|
* | 1 0 0 0 0 0 0 0 |
|
|
* | 0 1 0 0 0 0 0 0 |
|
|
* (V|I)' = | 0 0 1 0 0 0 0 0 |
|
|
* | 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
*
|
|
* Here we employ Gauss-Jordan elimination to find the inverse of (V|I)'. We
|
|
* have carefully chosen the seed values 1, 2, and 4 to ensure that this
|
|
* matrix is not singular.
|
|
* __ __
|
|
* | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 |
|
|
* | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 |
|
|
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
|
|
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
|
|
* | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 |
|
|
* | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 |
|
|
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
|
|
* | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 |
|
|
* | 0 205 116 0 0 0 0 0 0 1 19 29 64 16 4 1 |
|
|
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
|
|
* | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 |
|
|
* | 0 0 185 0 0 0 0 0 205 1 222 208 141 221 201 204 |
|
|
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
|
|
* | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 |
|
|
* | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 |
|
|
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 |
|
|
* | 0 1 0 0 0 0 0 0 167 100 5 41 159 169 217 208 |
|
|
* | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 |
|
|
* | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
* __ __
|
|
* | 0 0 1 0 0 0 0 0 |
|
|
* | 167 100 5 41 159 169 217 208 |
|
|
* | 166 100 4 40 158 168 216 209 |
|
|
* (V|I)'^-1 = | 0 0 0 1 0 0 0 0 |
|
|
* | 0 0 0 0 1 0 0 0 |
|
|
* | 0 0 0 0 0 1 0 0 |
|
|
* | 0 0 0 0 0 0 1 0 |
|
|
* | 0 0 0 0 0 0 0 1 |
|
|
* ~~ ~~
|
|
*
|
|
* We can then simply compute D = (V|I)'^-1 x (d|p)' to discover the values
|
|
* of the missing data.
|
|
*
|
|
* As is apparent from the example above, the only non-trivial rows in the
|
|
* inverse matrix correspond to the data disks that we're trying to
|
|
* reconstruct. Indeed, those are the only rows we need as the others would
|
|
* only be useful for reconstructing data known or assumed to be valid. For
|
|
* that reason, we only build the coefficients in the rows that correspond to
|
|
* targeted columns.
|
|
*/
|
|
/* END CSTYLED */
|
|
|
|
static void
|
|
vdev_raidz_matrix_init(raidz_map_t *rm, int n, int nmap, int *map,
|
|
uint8_t **rows)
|
|
{
|
|
int i, j;
|
|
int pow;
|
|
|
|
ASSERT(n == rm->rm_cols - rm->rm_firstdatacol);
|
|
|
|
/*
|
|
* Fill in the missing rows of interest.
|
|
*/
|
|
for (i = 0; i < nmap; i++) {
|
|
ASSERT3S(0, <=, map[i]);
|
|
ASSERT3S(map[i], <=, 2);
|
|
|
|
pow = map[i] * n;
|
|
if (pow > 255)
|
|
pow -= 255;
|
|
ASSERT(pow <= 255);
|
|
|
|
for (j = 0; j < n; j++) {
|
|
pow -= map[i];
|
|
if (pow < 0)
|
|
pow += 255;
|
|
rows[i][j] = vdev_raidz_pow2[pow];
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_matrix_invert(raidz_map_t *rm, int n, int nmissing, int *missing,
|
|
uint8_t **rows, uint8_t **invrows, const uint8_t *used)
|
|
{
|
|
int i, j, ii, jj;
|
|
uint8_t log;
|
|
|
|
/*
|
|
* Assert that the first nmissing entries from the array of used
|
|
* columns correspond to parity columns and that subsequent entries
|
|
* correspond to data columns.
|
|
*/
|
|
for (i = 0; i < nmissing; i++) {
|
|
ASSERT3S(used[i], <, rm->rm_firstdatacol);
|
|
}
|
|
for (; i < n; i++) {
|
|
ASSERT3S(used[i], >=, rm->rm_firstdatacol);
|
|
}
|
|
|
|
/*
|
|
* First initialize the storage where we'll compute the inverse rows.
|
|
*/
|
|
for (i = 0; i < nmissing; i++) {
|
|
for (j = 0; j < n; j++) {
|
|
invrows[i][j] = (i == j) ? 1 : 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Subtract all trivial rows from the rows of consequence.
|
|
*/
|
|
for (i = 0; i < nmissing; i++) {
|
|
for (j = nmissing; j < n; j++) {
|
|
ASSERT3U(used[j], >=, rm->rm_firstdatacol);
|
|
jj = used[j] - rm->rm_firstdatacol;
|
|
ASSERT3S(jj, <, n);
|
|
invrows[i][j] = rows[i][jj];
|
|
rows[i][jj] = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For each of the rows of interest, we must normalize it and subtract
|
|
* a multiple of it from the other rows.
|
|
*/
|
|
for (i = 0; i < nmissing; i++) {
|
|
for (j = 0; j < missing[i]; j++) {
|
|
ASSERT0(rows[i][j]);
|
|
}
|
|
ASSERT3U(rows[i][missing[i]], !=, 0);
|
|
|
|
/*
|
|
* Compute the inverse of the first element and multiply each
|
|
* element in the row by that value.
|
|
*/
|
|
log = 255 - vdev_raidz_log2[rows[i][missing[i]]];
|
|
|
|
for (j = 0; j < n; j++) {
|
|
rows[i][j] = vdev_raidz_exp2(rows[i][j], log);
|
|
invrows[i][j] = vdev_raidz_exp2(invrows[i][j], log);
|
|
}
|
|
|
|
for (ii = 0; ii < nmissing; ii++) {
|
|
if (i == ii)
|
|
continue;
|
|
|
|
ASSERT3U(rows[ii][missing[i]], !=, 0);
|
|
|
|
log = vdev_raidz_log2[rows[ii][missing[i]]];
|
|
|
|
for (j = 0; j < n; j++) {
|
|
rows[ii][j] ^=
|
|
vdev_raidz_exp2(rows[i][j], log);
|
|
invrows[ii][j] ^=
|
|
vdev_raidz_exp2(invrows[i][j], log);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Verify that the data that is left in the rows are properly part of
|
|
* an identity matrix.
|
|
*/
|
|
for (i = 0; i < nmissing; i++) {
|
|
for (j = 0; j < n; j++) {
|
|
if (j == missing[i]) {
|
|
ASSERT3U(rows[i][j], ==, 1);
|
|
} else {
|
|
ASSERT0(rows[i][j]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_matrix_reconstruct(raidz_map_t *rm, int n, int nmissing,
|
|
int *missing, uint8_t **invrows, const uint8_t *used)
|
|
{
|
|
int i, j, x, cc, c;
|
|
uint8_t *src;
|
|
uint64_t ccount;
|
|
uint8_t *dst[VDEV_RAIDZ_MAXPARITY];
|
|
uint64_t dcount[VDEV_RAIDZ_MAXPARITY];
|
|
uint8_t log = 0;
|
|
uint8_t val;
|
|
int ll;
|
|
uint8_t *invlog[VDEV_RAIDZ_MAXPARITY];
|
|
uint8_t *p, *pp;
|
|
size_t psize;
|
|
|
|
psize = sizeof (invlog[0][0]) * n * nmissing;
|
|
p = kmem_alloc(psize, KM_PUSHPAGE);
|
|
|
|
for (pp = p, i = 0; i < nmissing; i++) {
|
|
invlog[i] = pp;
|
|
pp += n;
|
|
}
|
|
|
|
for (i = 0; i < nmissing; i++) {
|
|
for (j = 0; j < n; j++) {
|
|
ASSERT3U(invrows[i][j], !=, 0);
|
|
invlog[i][j] = vdev_raidz_log2[invrows[i][j]];
|
|
}
|
|
}
|
|
|
|
for (i = 0; i < n; i++) {
|
|
c = used[i];
|
|
ASSERT3U(c, <, rm->rm_cols);
|
|
|
|
src = rm->rm_col[c].rc_data;
|
|
ccount = rm->rm_col[c].rc_size;
|
|
for (j = 0; j < nmissing; j++) {
|
|
cc = missing[j] + rm->rm_firstdatacol;
|
|
ASSERT3U(cc, >=, rm->rm_firstdatacol);
|
|
ASSERT3U(cc, <, rm->rm_cols);
|
|
ASSERT3U(cc, !=, c);
|
|
|
|
dst[j] = rm->rm_col[cc].rc_data;
|
|
dcount[j] = rm->rm_col[cc].rc_size;
|
|
}
|
|
|
|
ASSERT(ccount >= rm->rm_col[missing[0]].rc_size || i > 0);
|
|
|
|
for (x = 0; x < ccount; x++, src++) {
|
|
if (*src != 0)
|
|
log = vdev_raidz_log2[*src];
|
|
|
|
for (cc = 0; cc < nmissing; cc++) {
|
|
if (x >= dcount[cc])
|
|
continue;
|
|
|
|
if (*src == 0) {
|
|
val = 0;
|
|
} else {
|
|
if ((ll = log + invlog[cc][i]) >= 255)
|
|
ll -= 255;
|
|
val = vdev_raidz_pow2[ll];
|
|
}
|
|
|
|
if (i == 0)
|
|
dst[cc][x] = val;
|
|
else
|
|
dst[cc][x] ^= val;
|
|
}
|
|
}
|
|
}
|
|
|
|
kmem_free(p, psize);
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_reconstruct_general(raidz_map_t *rm, int *tgts, int ntgts)
|
|
{
|
|
int n, i, c, t, tt;
|
|
int nmissing_rows;
|
|
int missing_rows[VDEV_RAIDZ_MAXPARITY];
|
|
int parity_map[VDEV_RAIDZ_MAXPARITY];
|
|
|
|
uint8_t *p, *pp;
|
|
size_t psize;
|
|
|
|
uint8_t *rows[VDEV_RAIDZ_MAXPARITY];
|
|
uint8_t *invrows[VDEV_RAIDZ_MAXPARITY];
|
|
uint8_t *used;
|
|
|
|
int code = 0;
|
|
|
|
|
|
n = rm->rm_cols - rm->rm_firstdatacol;
|
|
|
|
/*
|
|
* Figure out which data columns are missing.
|
|
*/
|
|
nmissing_rows = 0;
|
|
for (t = 0; t < ntgts; t++) {
|
|
if (tgts[t] >= rm->rm_firstdatacol) {
|
|
missing_rows[nmissing_rows++] =
|
|
tgts[t] - rm->rm_firstdatacol;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Figure out which parity columns to use to help generate the missing
|
|
* data columns.
|
|
*/
|
|
for (tt = 0, c = 0, i = 0; i < nmissing_rows; c++) {
|
|
ASSERT(tt < ntgts);
|
|
ASSERT(c < rm->rm_firstdatacol);
|
|
|
|
/*
|
|
* Skip any targeted parity columns.
|
|
*/
|
|
if (c == tgts[tt]) {
|
|
tt++;
|
|
continue;
|
|
}
|
|
|
|
code |= 1 << c;
|
|
|
|
parity_map[i] = c;
|
|
i++;
|
|
}
|
|
|
|
ASSERT(code != 0);
|
|
ASSERT3U(code, <, 1 << VDEV_RAIDZ_MAXPARITY);
|
|
|
|
psize = (sizeof (rows[0][0]) + sizeof (invrows[0][0])) *
|
|
nmissing_rows * n + sizeof (used[0]) * n;
|
|
p = kmem_alloc(psize, KM_PUSHPAGE);
|
|
|
|
for (pp = p, i = 0; i < nmissing_rows; i++) {
|
|
rows[i] = pp;
|
|
pp += n;
|
|
invrows[i] = pp;
|
|
pp += n;
|
|
}
|
|
used = pp;
|
|
|
|
for (i = 0; i < nmissing_rows; i++) {
|
|
used[i] = parity_map[i];
|
|
}
|
|
|
|
for (tt = 0, c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
if (tt < nmissing_rows &&
|
|
c == missing_rows[tt] + rm->rm_firstdatacol) {
|
|
tt++;
|
|
continue;
|
|
}
|
|
|
|
ASSERT3S(i, <, n);
|
|
used[i] = c;
|
|
i++;
|
|
}
|
|
|
|
/*
|
|
* Initialize the interesting rows of the matrix.
|
|
*/
|
|
vdev_raidz_matrix_init(rm, n, nmissing_rows, parity_map, rows);
|
|
|
|
/*
|
|
* Invert the matrix.
|
|
*/
|
|
vdev_raidz_matrix_invert(rm, n, nmissing_rows, missing_rows, rows,
|
|
invrows, used);
|
|
|
|
/*
|
|
* Reconstruct the missing data using the generated matrix.
|
|
*/
|
|
vdev_raidz_matrix_reconstruct(rm, n, nmissing_rows, missing_rows,
|
|
invrows, used);
|
|
|
|
kmem_free(p, psize);
|
|
|
|
return (code);
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_reconstruct(raidz_map_t *rm, int *t, int nt)
|
|
{
|
|
int tgts[VDEV_RAIDZ_MAXPARITY], *dt;
|
|
int ntgts;
|
|
int i, c;
|
|
int code;
|
|
int nbadparity, nbaddata;
|
|
int parity_valid[VDEV_RAIDZ_MAXPARITY];
|
|
|
|
/*
|
|
* The tgts list must already be sorted.
|
|
*/
|
|
for (i = 1; i < nt; i++) {
|
|
ASSERT(t[i] > t[i - 1]);
|
|
}
|
|
|
|
nbadparity = rm->rm_firstdatacol;
|
|
nbaddata = rm->rm_cols - nbadparity;
|
|
ntgts = 0;
|
|
for (i = 0, c = 0; c < rm->rm_cols; c++) {
|
|
if (c < rm->rm_firstdatacol)
|
|
parity_valid[c] = B_FALSE;
|
|
|
|
if (i < nt && c == t[i]) {
|
|
tgts[ntgts++] = c;
|
|
i++;
|
|
} else if (rm->rm_col[c].rc_error != 0) {
|
|
tgts[ntgts++] = c;
|
|
} else if (c >= rm->rm_firstdatacol) {
|
|
nbaddata--;
|
|
} else {
|
|
parity_valid[c] = B_TRUE;
|
|
nbadparity--;
|
|
}
|
|
}
|
|
|
|
ASSERT(ntgts >= nt);
|
|
ASSERT(nbaddata >= 0);
|
|
ASSERT(nbaddata + nbadparity == ntgts);
|
|
|
|
dt = &tgts[nbadparity];
|
|
|
|
/*
|
|
* See if we can use any of our optimized reconstruction routines.
|
|
*/
|
|
if (!vdev_raidz_default_to_general) {
|
|
switch (nbaddata) {
|
|
case 1:
|
|
if (parity_valid[VDEV_RAIDZ_P])
|
|
return (vdev_raidz_reconstruct_p(rm, dt, 1));
|
|
|
|
ASSERT(rm->rm_firstdatacol > 1);
|
|
|
|
if (parity_valid[VDEV_RAIDZ_Q])
|
|
return (vdev_raidz_reconstruct_q(rm, dt, 1));
|
|
|
|
ASSERT(rm->rm_firstdatacol > 2);
|
|
break;
|
|
|
|
case 2:
|
|
ASSERT(rm->rm_firstdatacol > 1);
|
|
|
|
if (parity_valid[VDEV_RAIDZ_P] &&
|
|
parity_valid[VDEV_RAIDZ_Q])
|
|
return (vdev_raidz_reconstruct_pq(rm, dt, 2));
|
|
|
|
ASSERT(rm->rm_firstdatacol > 2);
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
code = vdev_raidz_reconstruct_general(rm, tgts, ntgts);
|
|
ASSERT(code < (1 << VDEV_RAIDZ_MAXPARITY));
|
|
ASSERT(code > 0);
|
|
return (code);
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_open(vdev_t *vd, uint64_t *asize, uint64_t *max_asize,
|
|
uint64_t *ashift)
|
|
{
|
|
vdev_t *cvd;
|
|
uint64_t nparity = vd->vdev_nparity;
|
|
int c;
|
|
int lasterror = 0;
|
|
int numerrors = 0;
|
|
|
|
ASSERT(nparity > 0);
|
|
|
|
if (nparity > VDEV_RAIDZ_MAXPARITY ||
|
|
vd->vdev_children < nparity + 1) {
|
|
vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
|
|
return (EINVAL);
|
|
}
|
|
|
|
vdev_open_children(vd);
|
|
|
|
for (c = 0; c < vd->vdev_children; c++) {
|
|
cvd = vd->vdev_child[c];
|
|
|
|
if (cvd->vdev_open_error != 0) {
|
|
lasterror = cvd->vdev_open_error;
|
|
numerrors++;
|
|
continue;
|
|
}
|
|
|
|
*asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1;
|
|
*max_asize = MIN(*max_asize - 1, cvd->vdev_max_asize - 1) + 1;
|
|
*ashift = MAX(*ashift, cvd->vdev_ashift);
|
|
}
|
|
|
|
*asize *= vd->vdev_children;
|
|
*max_asize *= vd->vdev_children;
|
|
|
|
if (numerrors > nparity) {
|
|
vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS;
|
|
return (lasterror);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_close(vdev_t *vd)
|
|
{
|
|
int c;
|
|
|
|
for (c = 0; c < vd->vdev_children; c++)
|
|
vdev_close(vd->vdev_child[c]);
|
|
}
|
|
|
|
static uint64_t
|
|
vdev_raidz_asize(vdev_t *vd, uint64_t psize)
|
|
{
|
|
uint64_t asize;
|
|
uint64_t ashift = vd->vdev_top->vdev_ashift;
|
|
uint64_t cols = vd->vdev_children;
|
|
uint64_t nparity = vd->vdev_nparity;
|
|
|
|
asize = ((psize - 1) >> ashift) + 1;
|
|
asize += nparity * ((asize + cols - nparity - 1) / (cols - nparity));
|
|
asize = roundup(asize, nparity + 1) << ashift;
|
|
|
|
return (asize);
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_child_done(zio_t *zio)
|
|
{
|
|
raidz_col_t *rc = zio->io_private;
|
|
|
|
rc->rc_error = zio->io_error;
|
|
rc->rc_tried = 1;
|
|
rc->rc_skipped = 0;
|
|
}
|
|
|
|
static int
|
|
vdev_raidz_io_start(zio_t *zio)
|
|
{
|
|
vdev_t *vd = zio->io_vd;
|
|
vdev_t *tvd = vd->vdev_top;
|
|
vdev_t *cvd;
|
|
raidz_map_t *rm;
|
|
raidz_col_t *rc;
|
|
int c, i;
|
|
|
|
rm = vdev_raidz_map_alloc(zio, tvd->vdev_ashift, vd->vdev_children,
|
|
vd->vdev_nparity);
|
|
|
|
ASSERT3U(rm->rm_asize, ==, vdev_psize_to_asize(vd, zio->io_size));
|
|
|
|
if (zio->io_type == ZIO_TYPE_WRITE) {
|
|
vdev_raidz_generate_parity(rm);
|
|
|
|
for (c = 0; c < rm->rm_cols; c++) {
|
|
rc = &rm->rm_col[c];
|
|
cvd = vd->vdev_child[rc->rc_devidx];
|
|
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
|
|
rc->rc_offset, rc->rc_data, rc->rc_size,
|
|
zio->io_type, zio->io_priority, 0,
|
|
vdev_raidz_child_done, rc));
|
|
}
|
|
|
|
/*
|
|
* Generate optional I/Os for any skipped sectors to improve
|
|
* aggregation contiguity.
|
|
*/
|
|
for (c = rm->rm_skipstart, i = 0; i < rm->rm_nskip; c++, i++) {
|
|
ASSERT(c <= rm->rm_scols);
|
|
if (c == rm->rm_scols)
|
|
c = 0;
|
|
rc = &rm->rm_col[c];
|
|
cvd = vd->vdev_child[rc->rc_devidx];
|
|
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
|
|
rc->rc_offset + rc->rc_size, NULL,
|
|
1 << tvd->vdev_ashift,
|
|
zio->io_type, zio->io_priority,
|
|
ZIO_FLAG_NODATA | ZIO_FLAG_OPTIONAL, NULL, NULL));
|
|
}
|
|
|
|
return (ZIO_PIPELINE_CONTINUE);
|
|
}
|
|
|
|
ASSERT(zio->io_type == ZIO_TYPE_READ);
|
|
|
|
/*
|
|
* 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 (c = rm->rm_cols - 1; c >= 0; c--) {
|
|
rc = &rm->rm_col[c];
|
|
cvd = vd->vdev_child[rc->rc_devidx];
|
|
if (!vdev_readable(cvd)) {
|
|
if (c >= rm->rm_firstdatacol)
|
|
rm->rm_missingdata++;
|
|
else
|
|
rm->rm_missingparity++;
|
|
rc->rc_error = ENXIO;
|
|
rc->rc_tried = 1; /* don't even try */
|
|
rc->rc_skipped = 1;
|
|
continue;
|
|
}
|
|
if (vdev_dtl_contains(cvd, DTL_MISSING, zio->io_txg, 1)) {
|
|
if (c >= rm->rm_firstdatacol)
|
|
rm->rm_missingdata++;
|
|
else
|
|
rm->rm_missingparity++;
|
|
rc->rc_error = ESTALE;
|
|
rc->rc_skipped = 1;
|
|
continue;
|
|
}
|
|
if (c >= rm->rm_firstdatacol || rm->rm_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_data, rc->rc_size,
|
|
zio->io_type, zio->io_priority, 0,
|
|
vdev_raidz_child_done, rc));
|
|
}
|
|
}
|
|
|
|
return (ZIO_PIPELINE_CONTINUE);
|
|
}
|
|
|
|
|
|
/*
|
|
* Report a checksum error for a child of a RAID-Z device.
|
|
*/
|
|
static void
|
|
raidz_checksum_error(zio_t *zio, raidz_col_t *rc, void *bad_data)
|
|
{
|
|
vdev_t *vd = zio->io_vd->vdev_child[rc->rc_devidx];
|
|
|
|
if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
|
|
zio_bad_cksum_t zbc;
|
|
raidz_map_t *rm = zio->io_vsd;
|
|
|
|
mutex_enter(&vd->vdev_stat_lock);
|
|
vd->vdev_stat.vs_checksum_errors++;
|
|
mutex_exit(&vd->vdev_stat_lock);
|
|
|
|
zbc.zbc_has_cksum = 0;
|
|
zbc.zbc_injected = rm->rm_ecksuminjected;
|
|
|
|
zfs_ereport_post_checksum(zio->io_spa, vd, zio,
|
|
rc->rc_offset, rc->rc_size, rc->rc_data, bad_data,
|
|
&zbc);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We keep track of whether or not there were any injected errors, so that
|
|
* any ereports we generate can note it.
|
|
*/
|
|
static int
|
|
raidz_checksum_verify(zio_t *zio)
|
|
{
|
|
zio_bad_cksum_t zbc;
|
|
raidz_map_t *rm = zio->io_vsd;
|
|
int ret;
|
|
|
|
bzero(&zbc, sizeof (zio_bad_cksum_t));
|
|
|
|
ret = zio_checksum_error(zio, &zbc);
|
|
if (ret != 0 && zbc.zbc_injected != 0)
|
|
rm->rm_ecksuminjected = 1;
|
|
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Generate the parity from the data columns. If we tried and were able to
|
|
* read the parity without error, verify that the generated parity matches the
|
|
* data we read. If it doesn't, we fire off a checksum error. Return the
|
|
* number such failures.
|
|
*/
|
|
static int
|
|
raidz_parity_verify(zio_t *zio, raidz_map_t *rm)
|
|
{
|
|
void *orig[VDEV_RAIDZ_MAXPARITY];
|
|
int c, ret = 0;
|
|
raidz_col_t *rc;
|
|
|
|
for (c = 0; c < rm->rm_firstdatacol; c++) {
|
|
rc = &rm->rm_col[c];
|
|
if (!rc->rc_tried || rc->rc_error != 0)
|
|
continue;
|
|
orig[c] = zio_buf_alloc(rc->rc_size);
|
|
bcopy(rc->rc_data, orig[c], rc->rc_size);
|
|
}
|
|
|
|
vdev_raidz_generate_parity(rm);
|
|
|
|
for (c = 0; c < rm->rm_firstdatacol; c++) {
|
|
rc = &rm->rm_col[c];
|
|
if (!rc->rc_tried || rc->rc_error != 0)
|
|
continue;
|
|
if (bcmp(orig[c], rc->rc_data, rc->rc_size) != 0) {
|
|
raidz_checksum_error(zio, rc, orig[c]);
|
|
rc->rc_error = ECKSUM;
|
|
ret++;
|
|
}
|
|
zio_buf_free(orig[c], rc->rc_size);
|
|
}
|
|
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Keep statistics on all the ways that we used parity to correct data.
|
|
*/
|
|
static uint64_t raidz_corrected[1 << VDEV_RAIDZ_MAXPARITY];
|
|
|
|
static int
|
|
vdev_raidz_worst_error(raidz_map_t *rm)
|
|
{
|
|
int c, error = 0;
|
|
|
|
for (c = 0; c < rm->rm_cols; c++)
|
|
error = zio_worst_error(error, rm->rm_col[c].rc_error);
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Iterate over all combinations of bad data and attempt a reconstruction.
|
|
* Note that the algorithm below is non-optimal because it doesn't take into
|
|
* account how reconstruction is actually performed. For example, with
|
|
* triple-parity RAID-Z the reconstruction procedure is the same if column 4
|
|
* is targeted as invalid as if columns 1 and 4 are targeted since in both
|
|
* cases we'd only use parity information in column 0.
|
|
*/
|
|
static int
|
|
vdev_raidz_combrec(zio_t *zio, int total_errors, int data_errors)
|
|
{
|
|
raidz_map_t *rm = zio->io_vsd;
|
|
raidz_col_t *rc;
|
|
void *orig[VDEV_RAIDZ_MAXPARITY];
|
|
int tstore[VDEV_RAIDZ_MAXPARITY + 2];
|
|
int *tgts = &tstore[1];
|
|
int curr, next, i, c, n;
|
|
int code, ret = 0;
|
|
|
|
ASSERT(total_errors < rm->rm_firstdatacol);
|
|
|
|
/*
|
|
* This simplifies one edge condition.
|
|
*/
|
|
tgts[-1] = -1;
|
|
|
|
for (n = 1; n <= rm->rm_firstdatacol - total_errors; n++) {
|
|
/*
|
|
* Initialize the targets array by finding the first n columns
|
|
* that contain no error.
|
|
*
|
|
* If there were no data errors, we need to ensure that we're
|
|
* always explicitly attempting to reconstruct at least one
|
|
* data column. To do this, we simply push the highest target
|
|
* up into the data columns.
|
|
*/
|
|
for (c = 0, i = 0; i < n; i++) {
|
|
if (i == n - 1 && data_errors == 0 &&
|
|
c < rm->rm_firstdatacol) {
|
|
c = rm->rm_firstdatacol;
|
|
}
|
|
|
|
while (rm->rm_col[c].rc_error != 0) {
|
|
c++;
|
|
ASSERT3S(c, <, rm->rm_cols);
|
|
}
|
|
|
|
tgts[i] = c++;
|
|
}
|
|
|
|
/*
|
|
* Setting tgts[n] simplifies the other edge condition.
|
|
*/
|
|
tgts[n] = rm->rm_cols;
|
|
|
|
/*
|
|
* These buffers were allocated in previous iterations.
|
|
*/
|
|
for (i = 0; i < n - 1; i++) {
|
|
ASSERT(orig[i] != NULL);
|
|
}
|
|
|
|
orig[n - 1] = zio_buf_alloc(rm->rm_col[0].rc_size);
|
|
|
|
curr = 0;
|
|
next = tgts[curr];
|
|
|
|
while (curr != n) {
|
|
tgts[curr] = next;
|
|
curr = 0;
|
|
|
|
/*
|
|
* Save off the original data that we're going to
|
|
* attempt to reconstruct.
|
|
*/
|
|
for (i = 0; i < n; i++) {
|
|
ASSERT(orig[i] != NULL);
|
|
c = tgts[i];
|
|
ASSERT3S(c, >=, 0);
|
|
ASSERT3S(c, <, rm->rm_cols);
|
|
rc = &rm->rm_col[c];
|
|
bcopy(rc->rc_data, orig[i], rc->rc_size);
|
|
}
|
|
|
|
/*
|
|
* Attempt a reconstruction and exit the outer loop on
|
|
* success.
|
|
*/
|
|
code = vdev_raidz_reconstruct(rm, tgts, n);
|
|
if (raidz_checksum_verify(zio) == 0) {
|
|
atomic_inc_64(&raidz_corrected[code]);
|
|
|
|
for (i = 0; i < n; i++) {
|
|
c = tgts[i];
|
|
rc = &rm->rm_col[c];
|
|
ASSERT(rc->rc_error == 0);
|
|
if (rc->rc_tried)
|
|
raidz_checksum_error(zio, rc,
|
|
orig[i]);
|
|
rc->rc_error = ECKSUM;
|
|
}
|
|
|
|
ret = code;
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* Restore the original data.
|
|
*/
|
|
for (i = 0; i < n; i++) {
|
|
c = tgts[i];
|
|
rc = &rm->rm_col[c];
|
|
bcopy(orig[i], rc->rc_data, rc->rc_size);
|
|
}
|
|
|
|
do {
|
|
/*
|
|
* Find the next valid column after the curr
|
|
* position..
|
|
*/
|
|
for (next = tgts[curr] + 1;
|
|
next < rm->rm_cols &&
|
|
rm->rm_col[next].rc_error != 0; next++)
|
|
continue;
|
|
|
|
ASSERT(next <= tgts[curr + 1]);
|
|
|
|
/*
|
|
* If that spot is available, we're done here.
|
|
*/
|
|
if (next != tgts[curr + 1])
|
|
break;
|
|
|
|
/*
|
|
* Otherwise, find the next valid column after
|
|
* the previous position.
|
|
*/
|
|
for (c = tgts[curr - 1] + 1;
|
|
rm->rm_col[c].rc_error != 0; c++)
|
|
continue;
|
|
|
|
tgts[curr] = c;
|
|
curr++;
|
|
|
|
} while (curr != n);
|
|
}
|
|
}
|
|
n--;
|
|
done:
|
|
for (i = 0; i < n; i++) {
|
|
zio_buf_free(orig[i], rm->rm_col[0].rc_size);
|
|
}
|
|
|
|
return (ret);
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_io_done(zio_t *zio)
|
|
{
|
|
vdev_t *vd = zio->io_vd;
|
|
vdev_t *cvd;
|
|
raidz_map_t *rm = zio->io_vsd;
|
|
raidz_col_t *rc = NULL;
|
|
int unexpected_errors = 0;
|
|
int parity_errors = 0;
|
|
int parity_untried = 0;
|
|
int data_errors = 0;
|
|
int total_errors = 0;
|
|
int n, c;
|
|
int tgts[VDEV_RAIDZ_MAXPARITY];
|
|
int code;
|
|
|
|
ASSERT(zio->io_bp != NULL); /* XXX need to add code to enforce this */
|
|
|
|
ASSERT(rm->rm_missingparity <= rm->rm_firstdatacol);
|
|
ASSERT(rm->rm_missingdata <= rm->rm_cols - rm->rm_firstdatacol);
|
|
|
|
for (c = 0; c < rm->rm_cols; c++) {
|
|
rc = &rm->rm_col[c];
|
|
|
|
if (rc->rc_error) {
|
|
ASSERT(rc->rc_error != ECKSUM); /* child has no bp */
|
|
|
|
if (c < rm->rm_firstdatacol)
|
|
parity_errors++;
|
|
else
|
|
data_errors++;
|
|
|
|
if (!rc->rc_skipped)
|
|
unexpected_errors++;
|
|
|
|
total_errors++;
|
|
} else if (c < rm->rm_firstdatacol && !rc->rc_tried) {
|
|
parity_untried++;
|
|
}
|
|
}
|
|
|
|
if (zio->io_type == ZIO_TYPE_WRITE) {
|
|
/*
|
|
* XXX -- for now, treat partial writes as a success.
|
|
* (If we couldn't write enough columns to reconstruct
|
|
* the data, the I/O failed. Otherwise, good enough.)
|
|
*
|
|
* Now that we support write reallocation, it would be better
|
|
* to treat partial failure as real failure unless there are
|
|
* no non-degraded top-level vdevs left, and not update DTLs
|
|
* if we intend to reallocate.
|
|
*/
|
|
/* XXPOLICY */
|
|
if (total_errors > rm->rm_firstdatacol)
|
|
zio->io_error = vdev_raidz_worst_error(rm);
|
|
|
|
return;
|
|
}
|
|
|
|
ASSERT(zio->io_type == ZIO_TYPE_READ);
|
|
/*
|
|
* There are three potential phases for a read:
|
|
* 1. produce valid data from the columns read
|
|
* 2. read all disks and try again
|
|
* 3. perform combinatorial reconstruction
|
|
*
|
|
* Each phase is progressively both more expensive and less likely to
|
|
* occur. If we encounter more errors than we can repair or all phases
|
|
* fail, we have no choice but to return an error.
|
|
*/
|
|
|
|
/*
|
|
* If the number of errors we saw was correctable -- less than or equal
|
|
* to the number of parity disks read -- attempt to produce data that
|
|
* has a valid checksum. Naturally, this case applies in the absence of
|
|
* any errors.
|
|
*/
|
|
if (total_errors <= rm->rm_firstdatacol - parity_untried) {
|
|
if (data_errors == 0) {
|
|
if (raidz_checksum_verify(zio) == 0) {
|
|
/*
|
|
* If we read parity information (unnecessarily
|
|
* as it happens since no reconstruction was
|
|
* needed) regenerate and verify the parity.
|
|
* We also regenerate parity when resilvering
|
|
* so we can write it out to the failed device
|
|
* later.
|
|
*/
|
|
if (parity_errors + parity_untried <
|
|
rm->rm_firstdatacol ||
|
|
(zio->io_flags & ZIO_FLAG_RESILVER)) {
|
|
n = raidz_parity_verify(zio, rm);
|
|
unexpected_errors += n;
|
|
ASSERT(parity_errors + n <=
|
|
rm->rm_firstdatacol);
|
|
}
|
|
goto done;
|
|
}
|
|
} else {
|
|
/*
|
|
* We either attempt to read all the parity columns or
|
|
* none of them. If we didn't try to read parity, we
|
|
* wouldn't be here in the correctable case. There must
|
|
* also have been fewer parity errors than parity
|
|
* columns or, again, we wouldn't be in this code path.
|
|
*/
|
|
ASSERT(parity_untried == 0);
|
|
ASSERT(parity_errors < rm->rm_firstdatacol);
|
|
|
|
/*
|
|
* Identify the data columns that reported an error.
|
|
*/
|
|
n = 0;
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
rc = &rm->rm_col[c];
|
|
if (rc->rc_error != 0) {
|
|
ASSERT(n < VDEV_RAIDZ_MAXPARITY);
|
|
tgts[n++] = c;
|
|
}
|
|
}
|
|
|
|
ASSERT(rm->rm_firstdatacol >= n);
|
|
|
|
code = vdev_raidz_reconstruct(rm, tgts, n);
|
|
|
|
if (raidz_checksum_verify(zio) == 0) {
|
|
atomic_inc_64(&raidz_corrected[code]);
|
|
|
|
/*
|
|
* If we read more parity disks than were used
|
|
* for reconstruction, confirm that the other
|
|
* parity disks produced correct data. This
|
|
* routine is suboptimal in that it regenerates
|
|
* the parity that we already used in addition
|
|
* to the parity that we're attempting to
|
|
* verify, but this should be a relatively
|
|
* uncommon case, and can be optimized if it
|
|
* becomes a problem. Note that we regenerate
|
|
* parity when resilvering so we can write it
|
|
* out to failed devices later.
|
|
*/
|
|
if (parity_errors < rm->rm_firstdatacol - n ||
|
|
(zio->io_flags & ZIO_FLAG_RESILVER)) {
|
|
n = raidz_parity_verify(zio, rm);
|
|
unexpected_errors += n;
|
|
ASSERT(parity_errors + n <=
|
|
rm->rm_firstdatacol);
|
|
}
|
|
|
|
goto done;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This isn't a typical situation -- either we got a read error or
|
|
* a child silently returned bad data. Read every block so we can
|
|
* try again with as much data and parity as we can track down. If
|
|
* we've already been through once before, all children will be marked
|
|
* as tried so we'll proceed to combinatorial reconstruction.
|
|
*/
|
|
unexpected_errors = 1;
|
|
rm->rm_missingdata = 0;
|
|
rm->rm_missingparity = 0;
|
|
|
|
for (c = 0; c < rm->rm_cols; c++) {
|
|
if (rm->rm_col[c].rc_tried)
|
|
continue;
|
|
|
|
zio_vdev_io_redone(zio);
|
|
do {
|
|
rc = &rm->rm_col[c];
|
|
if (rc->rc_tried)
|
|
continue;
|
|
zio_nowait(zio_vdev_child_io(zio, NULL,
|
|
vd->vdev_child[rc->rc_devidx],
|
|
rc->rc_offset, rc->rc_data, rc->rc_size,
|
|
zio->io_type, zio->io_priority, 0,
|
|
vdev_raidz_child_done, rc));
|
|
} while (++c < rm->rm_cols);
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* At this point we've attempted to reconstruct the data given the
|
|
* errors we detected, and we've attempted to read all columns. There
|
|
* must, therefore, be one or more additional problems -- silent errors
|
|
* resulting in invalid data rather than explicit I/O errors resulting
|
|
* in absent data. We check if there is enough additional data to
|
|
* possibly reconstruct the data and then perform combinatorial
|
|
* reconstruction over all possible combinations. If that fails,
|
|
* we're cooked.
|
|
*/
|
|
if (total_errors > rm->rm_firstdatacol) {
|
|
zio->io_error = vdev_raidz_worst_error(rm);
|
|
|
|
} else if (total_errors < rm->rm_firstdatacol &&
|
|
(code = vdev_raidz_combrec(zio, total_errors, data_errors)) != 0) {
|
|
/*
|
|
* If we didn't use all the available parity for the
|
|
* combinatorial reconstruction, verify that the remaining
|
|
* parity is correct.
|
|
*/
|
|
if (code != (1 << rm->rm_firstdatacol) - 1)
|
|
(void) raidz_parity_verify(zio, rm);
|
|
} else {
|
|
/*
|
|
* We're here because either:
|
|
*
|
|
* total_errors == rm_first_datacol, or
|
|
* vdev_raidz_combrec() failed
|
|
*
|
|
* In either case, there is enough bad data to prevent
|
|
* reconstruction.
|
|
*
|
|
* Start checksum ereports for all children which haven't
|
|
* failed, and the IO wasn't speculative.
|
|
*/
|
|
zio->io_error = ECKSUM;
|
|
|
|
if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
|
|
for (c = 0; c < rm->rm_cols; c++) {
|
|
rc = &rm->rm_col[c];
|
|
if (rc->rc_error == 0) {
|
|
zio_bad_cksum_t zbc;
|
|
zbc.zbc_has_cksum = 0;
|
|
zbc.zbc_injected =
|
|
rm->rm_ecksuminjected;
|
|
|
|
zfs_ereport_start_checksum(
|
|
zio->io_spa,
|
|
vd->vdev_child[rc->rc_devidx],
|
|
zio, rc->rc_offset, rc->rc_size,
|
|
(void *)(uintptr_t)c, &zbc);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
done:
|
|
zio_checksum_verified(zio);
|
|
|
|
if (zio->io_error == 0 && spa_writeable(zio->io_spa) &&
|
|
(unexpected_errors || (zio->io_flags & ZIO_FLAG_RESILVER))) {
|
|
/*
|
|
* Use the good data we have in hand to repair damaged children.
|
|
*/
|
|
for (c = 0; c < rm->rm_cols; c++) {
|
|
rc = &rm->rm_col[c];
|
|
cvd = vd->vdev_child[rc->rc_devidx];
|
|
|
|
if (rc->rc_error == 0)
|
|
continue;
|
|
|
|
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
|
|
rc->rc_offset, rc->rc_data, rc->rc_size,
|
|
ZIO_TYPE_WRITE, zio->io_priority,
|
|
ZIO_FLAG_IO_REPAIR | (unexpected_errors ?
|
|
ZIO_FLAG_SELF_HEAL : 0), NULL, NULL));
|
|
}
|
|
}
|
|
}
|
|
|
|
static void
|
|
vdev_raidz_state_change(vdev_t *vd, int faulted, int degraded)
|
|
{
|
|
if (faulted > vd->vdev_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);
|
|
}
|
|
|
|
vdev_ops_t vdev_raidz_ops = {
|
|
vdev_raidz_open,
|
|
vdev_raidz_close,
|
|
vdev_raidz_asize,
|
|
vdev_raidz_io_start,
|
|
vdev_raidz_io_done,
|
|
vdev_raidz_state_change,
|
|
NULL,
|
|
NULL,
|
|
VDEV_TYPE_RAIDZ, /* name of this vdev type */
|
|
B_FALSE /* not a leaf vdev */
|
|
};
|