2008-11-20 20:01:55 +00:00
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/*
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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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2008-12-03 20:09:06 +00:00
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* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
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2008-11-20 20:01:55 +00:00
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* Use is subject to license terms.
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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 both single and double parity. For single parity, we
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* use a simple XOR of all the data columns. For double parity, we use both
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* the simple XOR as well as a technique described in "The mathematics of
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* RAID-6" by H. Peter Anvin. This technique defines a Galois field, GF(2^8),
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* over the integers expressable in a single byte. Briefly, the operations on
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* the 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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*
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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 A^254.
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*
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* The two parity columns, P and Q, over several data columns, D_0, ... D_n-1,
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* 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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*
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* See the reconstruction code below for how P and Q can used individually or
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* 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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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; /* Column count */
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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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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_MAXPARITY 2
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#define VDEV_RAIDZ_MUL_2(a) (((a) << 1) ^ (((a) & 0x80) ? 0x1d : 0))
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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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/*
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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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2008-12-03 20:09:06 +00:00
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static void
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vdev_raidz_map_free(zio_t *zio)
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{
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raidz_map_t *rm = zio->io_vsd;
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int c;
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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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kmem_free(rm, offsetof(raidz_map_t, rm_col[rm->rm_cols]));
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}
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2008-11-20 20:01:55 +00:00
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static raidz_map_t *
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vdev_raidz_map_alloc(zio_t *zio, uint64_t unit_shift, uint64_t dcols,
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uint64_t nparity)
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{
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raidz_map_t *rm;
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uint64_t b = zio->io_offset >> unit_shift;
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uint64_t s = zio->io_size >> unit_shift;
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uint64_t f = b % dcols;
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uint64_t o = (b / dcols) << unit_shift;
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uint64_t q, r, c, bc, col, acols, coff, devidx;
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q = s / (dcols - nparity);
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r = s - q * (dcols - nparity);
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bc = (r == 0 ? 0 : r + nparity);
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acols = (q == 0 ? bc : dcols);
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rm = kmem_alloc(offsetof(raidz_map_t, rm_col[acols]), KM_SLEEP);
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rm->rm_cols = acols;
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rm->rm_bigcols = bc;
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rm->rm_asize = 0;
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rm->rm_missingdata = 0;
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rm->rm_missingparity = 0;
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rm->rm_firstdatacol = nparity;
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for (c = 0; c < acols; c++) {
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col = f + c;
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coff = o;
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if (col >= dcols) {
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col -= dcols;
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coff += 1ULL << unit_shift;
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}
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rm->rm_col[c].rc_devidx = col;
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rm->rm_col[c].rc_offset = coff;
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rm->rm_col[c].rc_size = (q + (c < bc)) << unit_shift;
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rm->rm_col[c].rc_data = NULL;
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rm->rm_col[c].rc_error = 0;
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rm->rm_col[c].rc_tried = 0;
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rm->rm_col[c].rc_skipped = 0;
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rm->rm_asize += rm->rm_col[c].rc_size;
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}
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rm->rm_asize = roundup(rm->rm_asize, (nparity + 1) << unit_shift);
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for (c = 0; c < rm->rm_firstdatacol; c++)
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rm->rm_col[c].rc_data = zio_buf_alloc(rm->rm_col[c].rc_size);
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rm->rm_col[c].rc_data = zio->io_data;
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for (c = c + 1; c < acols; c++)
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rm->rm_col[c].rc_data = (char *)rm->rm_col[c - 1].rc_data +
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rm->rm_col[c - 1].rc_size;
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/*
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* If all data stored spans all columns, there's a danger that parity
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* will always be on the same device and, since parity isn't read
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* during normal operation, that that device's I/O bandwidth won't be
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* used effectively. We therefore switch the parity every 1MB.
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*
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* ... at least that was, ostensibly, the theory. As a practical
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* matter unless we juggle the parity between all devices evenly, we
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* 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.
|
|
|
|
*/
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
|
|
|
zio->io_vsd = rm;
|
2008-12-03 20:09:06 +00:00
|
|
|
zio->io_vsd_free = vdev_raidz_map_free;
|
2008-11-20 20:01:55 +00:00
|
|
|
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++, p++, src++) {
|
|
|
|
*p = *src;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
ASSERT(ccount <= pcount);
|
|
|
|
for (i = 0; i < ccount; i++, p++, src++) {
|
|
|
|
*p ^= *src;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
vdev_raidz_generate_parity_pq(raidz_map_t *rm)
|
|
|
|
{
|
|
|
|
uint64_t *q, *p, *src, pcount, ccount, mask, i;
|
|
|
|
int c;
|
|
|
|
|
|
|
|
pcount = 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;
|
|
|
|
ccount = rm->rm_col[c].rc_size / sizeof (src[0]);
|
|
|
|
|
|
|
|
if (c == rm->rm_firstdatacol) {
|
|
|
|
ASSERT(ccount == pcount || ccount == 0);
|
|
|
|
for (i = 0; i < ccount; i++, p++, q++, src++) {
|
|
|
|
*q = *src;
|
|
|
|
*p = *src;
|
|
|
|
}
|
|
|
|
for (; i < pcount; i++, p++, q++, src++) {
|
|
|
|
*q = 0;
|
|
|
|
*p = 0;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
ASSERT(ccount <= pcount);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Rather than multiplying each byte individually (as
|
|
|
|
* described above), we are able to handle 8 at once
|
|
|
|
* by generating a mask based on the high bit in each
|
|
|
|
* byte and using that to conditionally XOR in 0x1d.
|
|
|
|
*/
|
|
|
|
for (i = 0; i < ccount; i++, p++, q++, src++) {
|
|
|
|
mask = *q & 0x8080808080808080ULL;
|
|
|
|
mask = (mask << 1) - (mask >> 7);
|
|
|
|
*q = ((*q << 1) & 0xfefefefefefefefeULL) ^
|
|
|
|
(mask & 0x1d1d1d1d1d1d1d1dULL);
|
|
|
|
*q ^= *src;
|
|
|
|
*p ^= *src;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Treat short columns as though they are full of 0s.
|
|
|
|
*/
|
|
|
|
for (; i < pcount; i++, q++) {
|
|
|
|
mask = *q & 0x8080808080808080ULL;
|
|
|
|
mask = (mask << 1) - (mask >> 7);
|
|
|
|
*q = ((*q << 1) & 0xfefefefefefefefeULL) ^
|
|
|
|
(mask & 0x1d1d1d1d1d1d1d1dULL);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
vdev_raidz_reconstruct_p(raidz_map_t *rm, int x)
|
|
|
|
{
|
|
|
|
uint64_t *dst, *src, xcount, ccount, count, i;
|
|
|
|
int c;
|
|
|
|
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
vdev_raidz_reconstruct_q(raidz_map_t *rm, int x)
|
|
|
|
{
|
|
|
|
uint64_t *dst, *src, xcount, ccount, count, mask, i;
|
|
|
|
uint8_t *b;
|
|
|
|
int c, j, exp;
|
|
|
|
|
|
|
|
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 an explanation of this, see the comment in
|
|
|
|
* vdev_raidz_generate_parity_pq() above.
|
|
|
|
*/
|
|
|
|
for (i = 0; i < count; i++, dst++, src++) {
|
|
|
|
mask = *dst & 0x8080808080808080ULL;
|
|
|
|
mask = (mask << 1) - (mask >> 7);
|
|
|
|
*dst = ((*dst << 1) & 0xfefefefefefefefeULL) ^
|
|
|
|
(mask & 0x1d1d1d1d1d1d1d1dULL);
|
|
|
|
*dst ^= *src;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (; i < xcount; i++, dst++) {
|
|
|
|
mask = *dst & 0x8080808080808080ULL;
|
|
|
|
mask = (mask << 1) - (mask >> 7);
|
|
|
|
*dst = ((*dst << 1) & 0xfefefefefefefefeULL) ^
|
|
|
|
(mask & 0x1d1d1d1d1d1d1d1dULL);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
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);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
|
|
|
vdev_raidz_reconstruct_pq(raidz_map_t *rm, int x, int y)
|
|
|
|
{
|
|
|
|
uint8_t *p, *q, *pxy, *qxy, *xd, *yd, tmp, a, b, aexp, bexp;
|
|
|
|
void *pdata, *qdata;
|
|
|
|
uint64_t xsize, ysize, i;
|
|
|
|
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
static int
|
|
|
|
vdev_raidz_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift)
|
|
|
|
{
|
|
|
|
vdev_t *cvd;
|
|
|
|
uint64_t nparity = vd->vdev_nparity;
|
|
|
|
int c, error;
|
|
|
|
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);
|
|
|
|
}
|
|
|
|
|
|
|
|
for (c = 0; c < vd->vdev_children; c++) {
|
|
|
|
cvd = vd->vdev_child[c];
|
|
|
|
|
|
|
|
if ((error = vdev_open(cvd)) != 0) {
|
|
|
|
lasterror = error;
|
|
|
|
numerrors++;
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
|
|
|
|
*asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1;
|
|
|
|
*ashift = MAX(*ashift, cvd->vdev_ashift);
|
|
|
|
}
|
|
|
|
|
|
|
|
*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;
|
|
|
|
blkptr_t *bp = zio->io_bp;
|
|
|
|
raidz_map_t *rm;
|
|
|
|
raidz_col_t *rc;
|
|
|
|
int c;
|
|
|
|
|
|
|
|
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) {
|
|
|
|
/*
|
|
|
|
* Generate RAID parity in the first virtual columns.
|
|
|
|
*/
|
|
|
|
if (rm->rm_firstdatacol == 1)
|
|
|
|
vdev_raidz_generate_parity_p(rm);
|
|
|
|
else
|
|
|
|
vdev_raidz_generate_parity_pq(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,
|
2008-12-03 20:09:06 +00:00
|
|
|
zio->io_type, zio->io_priority, 0,
|
2008-11-20 20:01:55 +00:00
|
|
|
vdev_raidz_child_done, rc));
|
|
|
|
}
|
|
|
|
|
2008-12-03 20:09:06 +00:00
|
|
|
return (ZIO_PIPELINE_CONTINUE);
|
2008-11-20 20:01:55 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
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
|
|
|
|
* data.
|
|
|
|
*/
|
|
|
|
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->vdev_dtl_map, bp->blk_birth, 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_nowait(zio_vdev_child_io(zio, NULL, cvd,
|
|
|
|
rc->rc_offset, rc->rc_data, rc->rc_size,
|
2008-12-03 20:09:06 +00:00
|
|
|
zio->io_type, zio->io_priority, 0,
|
2008-11-20 20:01:55 +00:00
|
|
|
vdev_raidz_child_done, rc));
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2008-12-03 20:09:06 +00:00
|
|
|
return (ZIO_PIPELINE_CONTINUE);
|
2008-11-20 20:01:55 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Report a checksum error for a child of a RAID-Z device.
|
|
|
|
*/
|
|
|
|
static void
|
|
|
|
raidz_checksum_error(zio_t *zio, raidz_col_t *rc)
|
|
|
|
{
|
|
|
|
vdev_t *vd = zio->io_vd->vdev_child[rc->rc_devidx];
|
|
|
|
|
|
|
|
if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
|
|
|
|
mutex_enter(&vd->vdev_stat_lock);
|
|
|
|
vd->vdev_stat.vs_checksum_errors++;
|
|
|
|
mutex_exit(&vd->vdev_stat_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE))
|
|
|
|
zfs_ereport_post(FM_EREPORT_ZFS_CHECKSUM,
|
|
|
|
zio->io_spa, vd, zio, rc->rc_offset, rc->rc_size);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* 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);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (rm->rm_firstdatacol == 1)
|
|
|
|
vdev_raidz_generate_parity_p(rm);
|
|
|
|
else
|
|
|
|
vdev_raidz_generate_parity_pq(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);
|
|
|
|
rc->rc_error = ECKSUM;
|
|
|
|
ret++;
|
|
|
|
}
|
|
|
|
zio_buf_free(orig[c], rc->rc_size);
|
|
|
|
}
|
|
|
|
|
|
|
|
return (ret);
|
|
|
|
}
|
|
|
|
|
|
|
|
static uint64_t raidz_corrected_p;
|
|
|
|
static uint64_t raidz_corrected_q;
|
|
|
|
static uint64_t raidz_corrected_pq;
|
|
|
|
|
|
|
|
static int
|
2008-12-03 20:09:06 +00:00
|
|
|
vdev_raidz_worst_error(raidz_map_t *rm)
|
|
|
|
{
|
|
|
|
int error = 0;
|
|
|
|
|
|
|
|
for (int c = 0; c < rm->rm_cols; c++)
|
|
|
|
error = zio_worst_error(error, rm->rm_col[c].rc_error);
|
|
|
|
|
|
|
|
return (error);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
2008-11-20 20:01:55 +00:00
|
|
|
vdev_raidz_io_done(zio_t *zio)
|
|
|
|
{
|
|
|
|
vdev_t *vd = zio->io_vd;
|
|
|
|
vdev_t *cvd;
|
|
|
|
raidz_map_t *rm = zio->io_vsd;
|
2008-11-20 22:04:00 +00:00
|
|
|
raidz_col_t *rc = NULL, *rc1;
|
2008-11-20 20:01:55 +00:00
|
|
|
int unexpected_errors = 0;
|
|
|
|
int parity_errors = 0;
|
|
|
|
int parity_untried = 0;
|
|
|
|
int data_errors = 0;
|
2008-12-03 20:09:06 +00:00
|
|
|
int total_errors = 0;
|
2008-11-20 20:01:55 +00:00
|
|
|
int n, c, c1;
|
|
|
|
|
|
|
|
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) {
|
2008-12-03 20:09:06 +00:00
|
|
|
ASSERT(rc->rc_error != ECKSUM); /* child has no bp */
|
2008-11-20 20:01:55 +00:00
|
|
|
|
|
|
|
if (c < rm->rm_firstdatacol)
|
|
|
|
parity_errors++;
|
|
|
|
else
|
|
|
|
data_errors++;
|
|
|
|
|
|
|
|
if (!rc->rc_skipped)
|
|
|
|
unexpected_errors++;
|
|
|
|
|
2008-12-03 20:09:06 +00:00
|
|
|
total_errors++;
|
2008-11-20 20:01:55 +00:00
|
|
|
} else if (c < rm->rm_firstdatacol && !rc->rc_tried) {
|
|
|
|
parity_untried++;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (zio->io_type == ZIO_TYPE_WRITE) {
|
|
|
|
/*
|
2008-12-03 20:09:06 +00:00
|
|
|
* 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.
|
2008-11-20 20:01:55 +00:00
|
|
|
*/
|
|
|
|
/* XXPOLICY */
|
2008-12-03 20:09:06 +00:00
|
|
|
if (total_errors > rm->rm_firstdatacol)
|
|
|
|
zio->io_error = vdev_raidz_worst_error(rm);
|
2008-11-20 20:01:55 +00:00
|
|
|
|
2008-12-03 20:09:06 +00:00
|
|
|
return;
|
2008-11-20 20:01:55 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
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.
|
|
|
|
*/
|
2008-12-03 20:09:06 +00:00
|
|
|
if (total_errors <= rm->rm_firstdatacol - parity_untried) {
|
2008-11-20 20:01:55 +00:00
|
|
|
switch (data_errors) {
|
|
|
|
case 0:
|
|
|
|
if (zio_checksum_error(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;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case 1:
|
|
|
|
/*
|
|
|
|
* 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);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Find the column that reported the error.
|
|
|
|
*/
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
if (rc->rc_error != 0)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
ASSERT(c != rm->rm_cols);
|
|
|
|
ASSERT(!rc->rc_skipped || rc->rc_error == ENXIO ||
|
|
|
|
rc->rc_error == ESTALE);
|
|
|
|
|
|
|
|
if (rm->rm_col[VDEV_RAIDZ_P].rc_error == 0) {
|
|
|
|
vdev_raidz_reconstruct_p(rm, c);
|
|
|
|
} else {
|
|
|
|
ASSERT(rm->rm_firstdatacol > 1);
|
|
|
|
vdev_raidz_reconstruct_q(rm, c);
|
|
|
|
}
|
|
|
|
|
|
|
|
if (zio_checksum_error(zio) == 0) {
|
|
|
|
if (rm->rm_col[VDEV_RAIDZ_P].rc_error == 0)
|
|
|
|
atomic_inc_64(&raidz_corrected_p);
|
|
|
|
else
|
|
|
|
atomic_inc_64(&raidz_corrected_q);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If there's more than one parity disk that
|
|
|
|
* was successfully read, confirm that the
|
|
|
|
* other parity disk produced the correct data.
|
|
|
|
* This routine is suboptimal in that it
|
|
|
|
* regenerates both the parity we wish to test
|
|
|
|
* as well as the parity we just used to
|
|
|
|
* perform the reconstruction, but this should
|
|
|
|
* be a relatively uncommon case, and can be
|
|
|
|
* optimized if it becomes a problem.
|
|
|
|
* We also regenerate parity when resilvering
|
|
|
|
* so we can write it out to the failed device
|
|
|
|
* later.
|
|
|
|
*/
|
|
|
|
if (parity_errors < rm->rm_firstdatacol - 1 ||
|
|
|
|
(zio->io_flags & ZIO_FLAG_RESILVER)) {
|
|
|
|
n = raidz_parity_verify(zio, rm);
|
|
|
|
unexpected_errors += n;
|
|
|
|
ASSERT(parity_errors + n <=
|
|
|
|
rm->rm_firstdatacol);
|
|
|
|
}
|
|
|
|
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
case 2:
|
|
|
|
/*
|
|
|
|
* Two data column errors require double parity.
|
|
|
|
*/
|
|
|
|
ASSERT(rm->rm_firstdatacol == 2);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Find the two columns that reported errors.
|
|
|
|
*/
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
if (rc->rc_error != 0)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
ASSERT(c != rm->rm_cols);
|
|
|
|
ASSERT(!rc->rc_skipped || rc->rc_error == ENXIO ||
|
|
|
|
rc->rc_error == ESTALE);
|
|
|
|
|
|
|
|
for (c1 = c++; c < rm->rm_cols; c++) {
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
if (rc->rc_error != 0)
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
ASSERT(c != rm->rm_cols);
|
|
|
|
ASSERT(!rc->rc_skipped || rc->rc_error == ENXIO ||
|
|
|
|
rc->rc_error == ESTALE);
|
|
|
|
|
|
|
|
vdev_raidz_reconstruct_pq(rm, c1, c);
|
|
|
|
|
|
|
|
if (zio_checksum_error(zio) == 0) {
|
|
|
|
atomic_inc_64(&raidz_corrected_pq);
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
break;
|
|
|
|
|
|
|
|
default:
|
|
|
|
ASSERT(rm->rm_firstdatacol <= 2);
|
|
|
|
ASSERT(0);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* 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,
|
2008-12-03 20:09:06 +00:00
|
|
|
zio->io_type, zio->io_priority, 0,
|
2008-11-20 20:01:55 +00:00
|
|
|
vdev_raidz_child_done, rc));
|
|
|
|
} while (++c < rm->rm_cols);
|
|
|
|
|
2008-12-03 20:09:06 +00:00
|
|
|
return;
|
2008-11-20 20:01:55 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* 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. Before we attempt combinatorial reconstruction make
|
|
|
|
* sure we have a chance of coming up with the right answer.
|
|
|
|
*/
|
2008-12-03 20:09:06 +00:00
|
|
|
if (total_errors >= rm->rm_firstdatacol) {
|
|
|
|
zio->io_error = vdev_raidz_worst_error(rm);
|
|
|
|
/*
|
|
|
|
* If there were exactly as many device errors as parity
|
|
|
|
* columns, yet we couldn't reconstruct the data, then at
|
|
|
|
* least one device must have returned bad data silently.
|
|
|
|
*/
|
|
|
|
if (total_errors == rm->rm_firstdatacol)
|
|
|
|
zio->io_error = zio_worst_error(zio->io_error, ECKSUM);
|
2008-11-20 20:01:55 +00:00
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (rm->rm_col[VDEV_RAIDZ_P].rc_error == 0) {
|
|
|
|
/*
|
|
|
|
* Attempt to reconstruct the data from parity P.
|
|
|
|
*/
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
|
|
void *orig;
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
|
|
|
|
orig = zio_buf_alloc(rc->rc_size);
|
|
|
|
bcopy(rc->rc_data, orig, rc->rc_size);
|
|
|
|
vdev_raidz_reconstruct_p(rm, c);
|
|
|
|
|
|
|
|
if (zio_checksum_error(zio) == 0) {
|
|
|
|
zio_buf_free(orig, rc->rc_size);
|
|
|
|
atomic_inc_64(&raidz_corrected_p);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this child didn't know that it returned
|
|
|
|
* bad data, inform it.
|
|
|
|
*/
|
|
|
|
if (rc->rc_tried && rc->rc_error == 0)
|
|
|
|
raidz_checksum_error(zio, rc);
|
|
|
|
rc->rc_error = ECKSUM;
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
bcopy(orig, rc->rc_data, rc->rc_size);
|
|
|
|
zio_buf_free(orig, rc->rc_size);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (rm->rm_firstdatacol > 1 && rm->rm_col[VDEV_RAIDZ_Q].rc_error == 0) {
|
|
|
|
/*
|
|
|
|
* Attempt to reconstruct the data from parity Q.
|
|
|
|
*/
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) {
|
|
|
|
void *orig;
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
|
|
|
|
orig = zio_buf_alloc(rc->rc_size);
|
|
|
|
bcopy(rc->rc_data, orig, rc->rc_size);
|
|
|
|
vdev_raidz_reconstruct_q(rm, c);
|
|
|
|
|
|
|
|
if (zio_checksum_error(zio) == 0) {
|
|
|
|
zio_buf_free(orig, rc->rc_size);
|
|
|
|
atomic_inc_64(&raidz_corrected_q);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this child didn't know that it returned
|
|
|
|
* bad data, inform it.
|
|
|
|
*/
|
|
|
|
if (rc->rc_tried && rc->rc_error == 0)
|
|
|
|
raidz_checksum_error(zio, rc);
|
|
|
|
rc->rc_error = ECKSUM;
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
bcopy(orig, rc->rc_data, rc->rc_size);
|
|
|
|
zio_buf_free(orig, rc->rc_size);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (rm->rm_firstdatacol > 1 &&
|
|
|
|
rm->rm_col[VDEV_RAIDZ_P].rc_error == 0 &&
|
|
|
|
rm->rm_col[VDEV_RAIDZ_Q].rc_error == 0) {
|
|
|
|
/*
|
|
|
|
* Attempt to reconstruct the data from both P and Q.
|
|
|
|
*/
|
|
|
|
for (c = rm->rm_firstdatacol; c < rm->rm_cols - 1; c++) {
|
|
|
|
void *orig, *orig1;
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
|
|
|
|
orig = zio_buf_alloc(rc->rc_size);
|
|
|
|
bcopy(rc->rc_data, orig, rc->rc_size);
|
|
|
|
|
|
|
|
for (c1 = c + 1; c1 < rm->rm_cols; c1++) {
|
|
|
|
rc1 = &rm->rm_col[c1];
|
|
|
|
|
|
|
|
orig1 = zio_buf_alloc(rc1->rc_size);
|
|
|
|
bcopy(rc1->rc_data, orig1, rc1->rc_size);
|
|
|
|
|
|
|
|
vdev_raidz_reconstruct_pq(rm, c, c1);
|
|
|
|
|
|
|
|
if (zio_checksum_error(zio) == 0) {
|
|
|
|
zio_buf_free(orig, rc->rc_size);
|
|
|
|
zio_buf_free(orig1, rc1->rc_size);
|
|
|
|
atomic_inc_64(&raidz_corrected_pq);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If these children didn't know they
|
|
|
|
* returned bad data, inform them.
|
|
|
|
*/
|
|
|
|
if (rc->rc_tried && rc->rc_error == 0)
|
|
|
|
raidz_checksum_error(zio, rc);
|
|
|
|
if (rc1->rc_tried && rc1->rc_error == 0)
|
|
|
|
raidz_checksum_error(zio, rc1);
|
|
|
|
|
|
|
|
rc->rc_error = ECKSUM;
|
|
|
|
rc1->rc_error = ECKSUM;
|
|
|
|
|
|
|
|
goto done;
|
|
|
|
}
|
|
|
|
|
|
|
|
bcopy(orig1, rc1->rc_data, rc1->rc_size);
|
|
|
|
zio_buf_free(orig1, rc1->rc_size);
|
|
|
|
}
|
|
|
|
|
|
|
|
bcopy(orig, rc->rc_data, rc->rc_size);
|
|
|
|
zio_buf_free(orig, rc->rc_size);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* All combinations failed to checksum. Generate checksum ereports for
|
|
|
|
* all children.
|
|
|
|
*/
|
|
|
|
zio->io_error = ECKSUM;
|
2008-12-03 20:09:06 +00:00
|
|
|
|
2008-11-20 20:01:55 +00:00
|
|
|
if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) {
|
|
|
|
for (c = 0; c < rm->rm_cols; c++) {
|
|
|
|
rc = &rm->rm_col[c];
|
|
|
|
zfs_ereport_post(FM_EREPORT_ZFS_CHECKSUM,
|
|
|
|
zio->io_spa, vd->vdev_child[rc->rc_devidx], zio,
|
|
|
|
rc->rc_offset, rc->rc_size);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
done:
|
|
|
|
zio_checksum_verified(zio);
|
|
|
|
|
|
|
|
if (zio->io_error == 0 && (spa_mode & FWRITE) &&
|
|
|
|
(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;
|
|
|
|
|
2008-12-03 20:09:06 +00:00
|
|
|
zio_nowait(zio_vdev_child_io(zio, NULL, cvd,
|
2008-11-20 20:01:55 +00:00
|
|
|
rc->rc_offset, rc->rc_data, rc->rc_size,
|
|
|
|
ZIO_TYPE_WRITE, zio->io_priority,
|
2008-12-03 20:09:06 +00:00
|
|
|
ZIO_FLAG_IO_REPAIR, NULL, NULL));
|
2008-11-20 20:01:55 +00:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
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,
|
|
|
|
VDEV_TYPE_RAIDZ, /* name of this vdev type */
|
|
|
|
B_FALSE /* not a leaf vdev */
|
|
|
|
};
|