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1 | /* |
2 | * CDDL HEADER START | |
3 | * | |
4 | * The contents of this file are subject to the terms of the | |
5 | * Common Development and Distribution License (the "License"). | |
6 | * You may not use this file except in compliance with the License. | |
7 | * | |
8 | * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE | |
9 | * or http://www.opensolaris.org/os/licensing. | |
10 | * See the License for the specific language governing permissions | |
11 | * and limitations under the License. | |
12 | * | |
13 | * When distributing Covered Code, include this CDDL HEADER in each | |
14 | * file and include the License file at usr/src/OPENSOLARIS.LICENSE. | |
15 | * If applicable, add the following below this CDDL HEADER, with the | |
16 | * fields enclosed by brackets "[]" replaced with your own identifying | |
17 | * information: Portions Copyright [yyyy] [name of copyright owner] | |
18 | * | |
19 | * CDDL HEADER END | |
20 | */ | |
21 | ||
22 | /* | |
9babb374 | 23 | * Copyright 2009 Sun Microsystems, Inc. All rights reserved. |
34dc7c2f BB |
24 | * Use is subject to license terms. |
25 | */ | |
26 | ||
34dc7c2f BB |
27 | #include <sys/zfs_context.h> |
28 | #include <sys/spa.h> | |
29 | #include <sys/vdev_impl.h> | |
30 | #include <sys/zio.h> | |
31 | #include <sys/zio_checksum.h> | |
32 | #include <sys/fs/zfs.h> | |
33 | #include <sys/fm/fs/zfs.h> | |
34 | ||
35 | /* | |
36 | * Virtual device vector for RAID-Z. | |
37 | * | |
45d1cae3 BB |
38 | * This vdev supports single, double, and triple parity. For single parity, |
39 | * we use a simple XOR of all the data columns. For double or triple parity, | |
40 | * we use a special case of Reed-Solomon coding. This extends the | |
41 | * technique described in "The mathematics of RAID-6" by H. Peter Anvin by | |
42 | * drawing on the system described in "A Tutorial on Reed-Solomon Coding for | |
43 | * Fault-Tolerance in RAID-like Systems" by James S. Plank on which the | |
44 | * former is also based. The latter is designed to provide higher performance | |
45 | * for writes. | |
46 | * | |
47 | * Note that the Plank paper claimed to support arbitrary N+M, but was then | |
48 | * amended six years later identifying a critical flaw that invalidates its | |
49 | * claims. Nevertheless, the technique can be adapted to work for up to | |
50 | * triple parity. For additional parity, the amendment "Note: Correction to | |
51 | * the 1997 Tutorial on Reed-Solomon Coding" by James S. Plank and Ying Ding | |
52 | * is viable, but the additional complexity means that write performance will | |
53 | * suffer. | |
54 | * | |
55 | * All of the methods above operate on a Galois field, defined over the | |
56 | * integers mod 2^N. In our case we choose N=8 for GF(8) so that all elements | |
57 | * can be expressed with a single byte. Briefly, the operations on the | |
58 | * field are defined as follows: | |
34dc7c2f BB |
59 | * |
60 | * o addition (+) is represented by a bitwise XOR | |
61 | * o subtraction (-) is therefore identical to addition: A + B = A - B | |
62 | * o multiplication of A by 2 is defined by the following bitwise expression: | |
63 | * (A * 2)_7 = A_6 | |
64 | * (A * 2)_6 = A_5 | |
65 | * (A * 2)_5 = A_4 | |
66 | * (A * 2)_4 = A_3 + A_7 | |
67 | * (A * 2)_3 = A_2 + A_7 | |
68 | * (A * 2)_2 = A_1 + A_7 | |
69 | * (A * 2)_1 = A_0 | |
70 | * (A * 2)_0 = A_7 | |
71 | * | |
72 | * In C, multiplying by 2 is therefore ((a << 1) ^ ((a & 0x80) ? 0x1d : 0)). | |
45d1cae3 BB |
73 | * As an aside, this multiplication is derived from the error correcting |
74 | * primitive polynomial x^8 + x^4 + x^3 + x^2 + 1. | |
34dc7c2f BB |
75 | * |
76 | * Observe that any number in the field (except for 0) can be expressed as a | |
77 | * power of 2 -- a generator for the field. We store a table of the powers of | |
78 | * 2 and logs base 2 for quick look ups, and exploit the fact that A * B can | |
79 | * be rewritten as 2^(log_2(A) + log_2(B)) (where '+' is normal addition rather | |
45d1cae3 BB |
80 | * than field addition). The inverse of a field element A (A^-1) is therefore |
81 | * A ^ (255 - 1) = A^254. | |
34dc7c2f | 82 | * |
45d1cae3 BB |
83 | * The up-to-three parity columns, P, Q, R over several data columns, |
84 | * D_0, ... D_n-1, can be expressed by field operations: | |
34dc7c2f BB |
85 | * |
86 | * P = D_0 + D_1 + ... + D_n-2 + D_n-1 | |
87 | * Q = 2^n-1 * D_0 + 2^n-2 * D_1 + ... + 2^1 * D_n-2 + 2^0 * D_n-1 | |
88 | * = ((...((D_0) * 2 + D_1) * 2 + ...) * 2 + D_n-2) * 2 + D_n-1 | |
45d1cae3 BB |
89 | * R = 4^n-1 * D_0 + 4^n-2 * D_1 + ... + 4^1 * D_n-2 + 4^0 * D_n-1 |
90 | * = ((...((D_0) * 4 + D_1) * 4 + ...) * 4 + D_n-2) * 4 + D_n-1 | |
34dc7c2f | 91 | * |
45d1cae3 BB |
92 | * We chose 1, 2, and 4 as our generators because 1 corresponds to the trival |
93 | * XOR operation, and 2 and 4 can be computed quickly and generate linearly- | |
94 | * independent coefficients. (There are no additional coefficients that have | |
95 | * this property which is why the uncorrected Plank method breaks down.) | |
96 | * | |
97 | * See the reconstruction code below for how P, Q and R can used individually | |
98 | * or in concert to recover missing data columns. | |
34dc7c2f BB |
99 | */ |
100 | ||
101 | typedef struct raidz_col { | |
102 | uint64_t rc_devidx; /* child device index for I/O */ | |
103 | uint64_t rc_offset; /* device offset */ | |
104 | uint64_t rc_size; /* I/O size */ | |
105 | void *rc_data; /* I/O data */ | |
106 | int rc_error; /* I/O error for this device */ | |
107 | uint8_t rc_tried; /* Did we attempt this I/O column? */ | |
108 | uint8_t rc_skipped; /* Did we skip this I/O column? */ | |
109 | } raidz_col_t; | |
110 | ||
111 | typedef struct raidz_map { | |
45d1cae3 BB |
112 | uint64_t rm_cols; /* Regular column count */ |
113 | uint64_t rm_scols; /* Count including skipped columns */ | |
34dc7c2f BB |
114 | uint64_t rm_bigcols; /* Number of oversized columns */ |
115 | uint64_t rm_asize; /* Actual total I/O size */ | |
116 | uint64_t rm_missingdata; /* Count of missing data devices */ | |
117 | uint64_t rm_missingparity; /* Count of missing parity devices */ | |
118 | uint64_t rm_firstdatacol; /* First data column/parity count */ | |
45d1cae3 | 119 | uint64_t rm_skipped; /* Skipped sectors for padding */ |
34dc7c2f BB |
120 | raidz_col_t rm_col[1]; /* Flexible array of I/O columns */ |
121 | } raidz_map_t; | |
122 | ||
123 | #define VDEV_RAIDZ_P 0 | |
124 | #define VDEV_RAIDZ_Q 1 | |
45d1cae3 BB |
125 | #define VDEV_RAIDZ_R 2 |
126 | #define VDEV_RAIDZ_MAXPARITY 3 | |
127 | ||
128 | #define VDEV_RAIDZ_MUL_2(x) (((x) << 1) ^ (((x) & 0x80) ? 0x1d : 0)) | |
129 | #define VDEV_RAIDZ_MUL_4(x) (VDEV_RAIDZ_MUL_2(VDEV_RAIDZ_MUL_2(x))) | |
130 | ||
131 | /* | |
132 | * We provide a mechanism to perform the field multiplication operation on a | |
133 | * 64-bit value all at once rather than a byte at a time. This works by | |
134 | * creating a mask from the top bit in each byte and using that to | |
135 | * conditionally apply the XOR of 0x1d. | |
136 | */ | |
137 | #define VDEV_RAIDZ_64MUL_2(x, mask) \ | |
138 | { \ | |
139 | (mask) = (x) & 0x8080808080808080ULL; \ | |
140 | (mask) = ((mask) << 1) - ((mask) >> 7); \ | |
141 | (x) = (((x) << 1) & 0xfefefefefefefefeULL) ^ \ | |
142 | ((mask) & 0x1d1d1d1d1d1d1d1d); \ | |
143 | } | |
34dc7c2f | 144 | |
45d1cae3 BB |
145 | #define VDEV_RAIDZ_64MUL_4(x, mask) \ |
146 | { \ | |
147 | VDEV_RAIDZ_64MUL_2((x), mask); \ | |
148 | VDEV_RAIDZ_64MUL_2((x), mask); \ | |
149 | } | |
34dc7c2f | 150 | |
45d1cae3 BB |
151 | /* |
152 | * Force reconstruction to use the general purpose method. | |
153 | */ | |
154 | int vdev_raidz_default_to_general; | |
34dc7c2f BB |
155 | |
156 | /* | |
157 | * These two tables represent powers and logs of 2 in the Galois field defined | |
158 | * above. These values were computed by repeatedly multiplying by 2 as above. | |
159 | */ | |
160 | static const uint8_t vdev_raidz_pow2[256] = { | |
161 | 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, | |
162 | 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26, | |
163 | 0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, | |
164 | 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0, | |
165 | 0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, | |
166 | 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23, | |
167 | 0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, | |
168 | 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1, | |
169 | 0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, | |
170 | 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0, | |
171 | 0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, | |
172 | 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2, | |
173 | 0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, | |
174 | 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce, | |
175 | 0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, | |
176 | 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc, | |
177 | 0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, | |
178 | 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54, | |
179 | 0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, | |
180 | 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73, | |
181 | 0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, | |
182 | 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff, | |
183 | 0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, | |
184 | 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41, | |
185 | 0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, | |
186 | 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6, | |
187 | 0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, | |
188 | 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09, | |
189 | 0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, | |
190 | 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16, | |
191 | 0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, | |
192 | 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x01 | |
193 | }; | |
194 | static const uint8_t vdev_raidz_log2[256] = { | |
195 | 0x00, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, | |
196 | 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b, | |
197 | 0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, | |
198 | 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71, | |
199 | 0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, | |
200 | 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45, | |
201 | 0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, | |
202 | 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6, | |
203 | 0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, | |
204 | 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88, | |
205 | 0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, | |
206 | 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40, | |
207 | 0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, | |
208 | 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d, | |
209 | 0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, | |
210 | 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57, | |
211 | 0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, | |
212 | 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18, | |
213 | 0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, | |
214 | 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e, | |
215 | 0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, | |
216 | 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61, | |
217 | 0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, | |
218 | 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2, | |
219 | 0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, | |
220 | 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6, | |
221 | 0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, | |
222 | 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a, | |
223 | 0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, | |
224 | 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7, | |
225 | 0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, | |
226 | 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf, | |
227 | }; | |
228 | ||
229 | /* | |
230 | * Multiply a given number by 2 raised to the given power. | |
231 | */ | |
232 | static uint8_t | |
233 | vdev_raidz_exp2(uint_t a, int exp) | |
234 | { | |
235 | if (a == 0) | |
236 | return (0); | |
237 | ||
238 | ASSERT(exp >= 0); | |
239 | ASSERT(vdev_raidz_log2[a] > 0 || a == 1); | |
240 | ||
241 | exp += vdev_raidz_log2[a]; | |
242 | if (exp > 255) | |
243 | exp -= 255; | |
244 | ||
245 | return (vdev_raidz_pow2[exp]); | |
246 | } | |
247 | ||
b128c09f BB |
248 | static void |
249 | vdev_raidz_map_free(zio_t *zio) | |
250 | { | |
251 | raidz_map_t *rm = zio->io_vsd; | |
252 | int c; | |
253 | ||
254 | for (c = 0; c < rm->rm_firstdatacol; c++) | |
255 | zio_buf_free(rm->rm_col[c].rc_data, rm->rm_col[c].rc_size); | |
256 | ||
45d1cae3 | 257 | kmem_free(rm, offsetof(raidz_map_t, rm_col[rm->rm_scols])); |
b128c09f BB |
258 | } |
259 | ||
34dc7c2f BB |
260 | static raidz_map_t * |
261 | vdev_raidz_map_alloc(zio_t *zio, uint64_t unit_shift, uint64_t dcols, | |
262 | uint64_t nparity) | |
263 | { | |
264 | raidz_map_t *rm; | |
265 | uint64_t b = zio->io_offset >> unit_shift; | |
266 | uint64_t s = zio->io_size >> unit_shift; | |
267 | uint64_t f = b % dcols; | |
268 | uint64_t o = (b / dcols) << unit_shift; | |
45d1cae3 | 269 | uint64_t q, r, c, bc, col, acols, scols, coff, devidx, asize, tot; |
34dc7c2f BB |
270 | |
271 | q = s / (dcols - nparity); | |
272 | r = s - q * (dcols - nparity); | |
273 | bc = (r == 0 ? 0 : r + nparity); | |
45d1cae3 BB |
274 | tot = s + nparity * (q + (r == 0 ? 0 : 1)); |
275 | ||
276 | if (q == 0) { | |
277 | acols = bc; | |
278 | scols = MIN(dcols, roundup(bc, nparity + 1)); | |
279 | } else { | |
280 | acols = dcols; | |
281 | scols = dcols; | |
282 | } | |
34dc7c2f | 283 | |
45d1cae3 | 284 | ASSERT3U(acols, <=, scols); |
34dc7c2f | 285 | |
45d1cae3 | 286 | rm = kmem_alloc(offsetof(raidz_map_t, rm_col[scols]), KM_SLEEP); |
34dc7c2f BB |
287 | |
288 | rm->rm_cols = acols; | |
45d1cae3 | 289 | rm->rm_scols = scols; |
34dc7c2f | 290 | rm->rm_bigcols = bc; |
34dc7c2f BB |
291 | rm->rm_missingdata = 0; |
292 | rm->rm_missingparity = 0; | |
293 | rm->rm_firstdatacol = nparity; | |
294 | ||
45d1cae3 BB |
295 | asize = 0; |
296 | ||
297 | for (c = 0; c < scols; c++) { | |
34dc7c2f BB |
298 | col = f + c; |
299 | coff = o; | |
300 | if (col >= dcols) { | |
301 | col -= dcols; | |
302 | coff += 1ULL << unit_shift; | |
303 | } | |
304 | rm->rm_col[c].rc_devidx = col; | |
305 | rm->rm_col[c].rc_offset = coff; | |
34dc7c2f BB |
306 | rm->rm_col[c].rc_data = NULL; |
307 | rm->rm_col[c].rc_error = 0; | |
308 | rm->rm_col[c].rc_tried = 0; | |
309 | rm->rm_col[c].rc_skipped = 0; | |
45d1cae3 BB |
310 | |
311 | if (c >= acols) | |
312 | rm->rm_col[c].rc_size = 0; | |
313 | else if (c < bc) | |
314 | rm->rm_col[c].rc_size = (q + 1) << unit_shift; | |
315 | else | |
316 | rm->rm_col[c].rc_size = q << unit_shift; | |
317 | ||
318 | asize += rm->rm_col[c].rc_size; | |
34dc7c2f BB |
319 | } |
320 | ||
45d1cae3 BB |
321 | ASSERT3U(asize, ==, tot << unit_shift); |
322 | rm->rm_asize = roundup(asize, (nparity + 1) << unit_shift); | |
323 | rm->rm_skipped = roundup(tot, nparity + 1) - tot; | |
324 | ASSERT3U(rm->rm_asize - asize, ==, rm->rm_skipped << unit_shift); | |
325 | ASSERT3U(rm->rm_skipped, <=, nparity); | |
34dc7c2f BB |
326 | |
327 | for (c = 0; c < rm->rm_firstdatacol; c++) | |
328 | rm->rm_col[c].rc_data = zio_buf_alloc(rm->rm_col[c].rc_size); | |
329 | ||
330 | rm->rm_col[c].rc_data = zio->io_data; | |
331 | ||
332 | for (c = c + 1; c < acols; c++) | |
333 | rm->rm_col[c].rc_data = (char *)rm->rm_col[c - 1].rc_data + | |
334 | rm->rm_col[c - 1].rc_size; | |
335 | ||
336 | /* | |
337 | * If all data stored spans all columns, there's a danger that parity | |
338 | * will always be on the same device and, since parity isn't read | |
339 | * during normal operation, that that device's I/O bandwidth won't be | |
340 | * used effectively. We therefore switch the parity every 1MB. | |
341 | * | |
342 | * ... at least that was, ostensibly, the theory. As a practical | |
343 | * matter unless we juggle the parity between all devices evenly, we | |
344 | * won't see any benefit. Further, occasional writes that aren't a | |
345 | * multiple of the LCM of the number of children and the minimum | |
346 | * stripe width are sufficient to avoid pessimal behavior. | |
347 | * Unfortunately, this decision created an implicit on-disk format | |
348 | * requirement that we need to support for all eternity, but only | |
349 | * for single-parity RAID-Z. | |
350 | */ | |
351 | ASSERT(rm->rm_cols >= 2); | |
352 | ASSERT(rm->rm_col[0].rc_size == rm->rm_col[1].rc_size); | |
353 | ||
354 | if (rm->rm_firstdatacol == 1 && (zio->io_offset & (1ULL << 20))) { | |
355 | devidx = rm->rm_col[0].rc_devidx; | |
356 | o = rm->rm_col[0].rc_offset; | |
357 | rm->rm_col[0].rc_devidx = rm->rm_col[1].rc_devidx; | |
358 | rm->rm_col[0].rc_offset = rm->rm_col[1].rc_offset; | |
359 | rm->rm_col[1].rc_devidx = devidx; | |
360 | rm->rm_col[1].rc_offset = o; | |
361 | } | |
362 | ||
363 | zio->io_vsd = rm; | |
b128c09f | 364 | zio->io_vsd_free = vdev_raidz_map_free; |
34dc7c2f BB |
365 | return (rm); |
366 | } | |
367 | ||
34dc7c2f BB |
368 | static void |
369 | vdev_raidz_generate_parity_p(raidz_map_t *rm) | |
370 | { | |
371 | uint64_t *p, *src, pcount, ccount, i; | |
372 | int c; | |
373 | ||
374 | pcount = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]); | |
375 | ||
376 | for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { | |
377 | src = rm->rm_col[c].rc_data; | |
378 | p = rm->rm_col[VDEV_RAIDZ_P].rc_data; | |
379 | ccount = rm->rm_col[c].rc_size / sizeof (src[0]); | |
380 | ||
381 | if (c == rm->rm_firstdatacol) { | |
382 | ASSERT(ccount == pcount); | |
45d1cae3 | 383 | for (i = 0; i < ccount; i++, src++, p++) { |
34dc7c2f BB |
384 | *p = *src; |
385 | } | |
386 | } else { | |
387 | ASSERT(ccount <= pcount); | |
45d1cae3 | 388 | for (i = 0; i < ccount; i++, src++, p++) { |
34dc7c2f BB |
389 | *p ^= *src; |
390 | } | |
391 | } | |
392 | } | |
393 | } | |
394 | ||
395 | static void | |
396 | vdev_raidz_generate_parity_pq(raidz_map_t *rm) | |
397 | { | |
45d1cae3 | 398 | uint64_t *p, *q, *src, pcnt, ccnt, mask, i; |
34dc7c2f BB |
399 | int c; |
400 | ||
45d1cae3 | 401 | pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]); |
34dc7c2f BB |
402 | ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size == |
403 | rm->rm_col[VDEV_RAIDZ_Q].rc_size); | |
404 | ||
405 | for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { | |
406 | src = rm->rm_col[c].rc_data; | |
407 | p = rm->rm_col[VDEV_RAIDZ_P].rc_data; | |
408 | q = rm->rm_col[VDEV_RAIDZ_Q].rc_data; | |
45d1cae3 BB |
409 | |
410 | ccnt = rm->rm_col[c].rc_size / sizeof (src[0]); | |
34dc7c2f BB |
411 | |
412 | if (c == rm->rm_firstdatacol) { | |
45d1cae3 BB |
413 | ASSERT(ccnt == pcnt || ccnt == 0); |
414 | for (i = 0; i < ccnt; i++, src++, p++, q++) { | |
34dc7c2f | 415 | *p = *src; |
45d1cae3 | 416 | *q = *src; |
34dc7c2f | 417 | } |
45d1cae3 | 418 | for (; i < pcnt; i++, src++, p++, q++) { |
34dc7c2f | 419 | *p = 0; |
45d1cae3 | 420 | *q = 0; |
34dc7c2f BB |
421 | } |
422 | } else { | |
45d1cae3 | 423 | ASSERT(ccnt <= pcnt); |
34dc7c2f BB |
424 | |
425 | /* | |
45d1cae3 BB |
426 | * Apply the algorithm described above by multiplying |
427 | * the previous result and adding in the new value. | |
34dc7c2f | 428 | */ |
45d1cae3 BB |
429 | for (i = 0; i < ccnt; i++, src++, p++, q++) { |
430 | *p ^= *src; | |
431 | ||
432 | VDEV_RAIDZ_64MUL_2(*q, mask); | |
34dc7c2f | 433 | *q ^= *src; |
45d1cae3 BB |
434 | } |
435 | ||
436 | /* | |
437 | * Treat short columns as though they are full of 0s. | |
438 | * Note that there's therefore nothing needed for P. | |
439 | */ | |
440 | for (; i < pcnt; i++, q++) { | |
441 | VDEV_RAIDZ_64MUL_2(*q, mask); | |
442 | } | |
443 | } | |
444 | } | |
445 | } | |
446 | ||
447 | static void | |
448 | vdev_raidz_generate_parity_pqr(raidz_map_t *rm) | |
449 | { | |
450 | uint64_t *p, *q, *r, *src, pcnt, ccnt, mask, i; | |
451 | int c; | |
452 | ||
453 | pcnt = rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0]); | |
454 | ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size == | |
455 | rm->rm_col[VDEV_RAIDZ_Q].rc_size); | |
456 | ASSERT(rm->rm_col[VDEV_RAIDZ_P].rc_size == | |
457 | rm->rm_col[VDEV_RAIDZ_R].rc_size); | |
458 | ||
459 | for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { | |
460 | src = rm->rm_col[c].rc_data; | |
461 | p = rm->rm_col[VDEV_RAIDZ_P].rc_data; | |
462 | q = rm->rm_col[VDEV_RAIDZ_Q].rc_data; | |
463 | r = rm->rm_col[VDEV_RAIDZ_R].rc_data; | |
464 | ||
465 | ccnt = rm->rm_col[c].rc_size / sizeof (src[0]); | |
466 | ||
467 | if (c == rm->rm_firstdatacol) { | |
468 | ASSERT(ccnt == pcnt || ccnt == 0); | |
469 | for (i = 0; i < ccnt; i++, src++, p++, q++, r++) { | |
470 | *p = *src; | |
471 | *q = *src; | |
472 | *r = *src; | |
473 | } | |
474 | for (; i < pcnt; i++, src++, p++, q++, r++) { | |
475 | *p = 0; | |
476 | *q = 0; | |
477 | *r = 0; | |
478 | } | |
479 | } else { | |
480 | ASSERT(ccnt <= pcnt); | |
481 | ||
482 | /* | |
483 | * Apply the algorithm described above by multiplying | |
484 | * the previous result and adding in the new value. | |
485 | */ | |
486 | for (i = 0; i < ccnt; i++, src++, p++, q++, r++) { | |
34dc7c2f | 487 | *p ^= *src; |
45d1cae3 BB |
488 | |
489 | VDEV_RAIDZ_64MUL_2(*q, mask); | |
490 | *q ^= *src; | |
491 | ||
492 | VDEV_RAIDZ_64MUL_4(*r, mask); | |
493 | *r ^= *src; | |
34dc7c2f BB |
494 | } |
495 | ||
496 | /* | |
497 | * Treat short columns as though they are full of 0s. | |
45d1cae3 | 498 | * Note that there's therefore nothing needed for P. |
34dc7c2f | 499 | */ |
45d1cae3 BB |
500 | for (; i < pcnt; i++, q++, r++) { |
501 | VDEV_RAIDZ_64MUL_2(*q, mask); | |
502 | VDEV_RAIDZ_64MUL_4(*r, mask); | |
34dc7c2f BB |
503 | } |
504 | } | |
505 | } | |
506 | } | |
507 | ||
45d1cae3 BB |
508 | /* |
509 | * Generate RAID parity in the first virtual columns according to the number of | |
510 | * parity columns available. | |
511 | */ | |
34dc7c2f | 512 | static void |
45d1cae3 BB |
513 | vdev_raidz_generate_parity(raidz_map_t *rm) |
514 | { | |
515 | switch (rm->rm_firstdatacol) { | |
516 | case 1: | |
517 | vdev_raidz_generate_parity_p(rm); | |
518 | break; | |
519 | case 2: | |
520 | vdev_raidz_generate_parity_pq(rm); | |
521 | break; | |
522 | case 3: | |
523 | vdev_raidz_generate_parity_pqr(rm); | |
524 | break; | |
525 | default: | |
526 | cmn_err(CE_PANIC, "invalid RAID-Z configuration"); | |
527 | } | |
528 | } | |
529 | ||
530 | static int | |
531 | vdev_raidz_reconstruct_p(raidz_map_t *rm, int *tgts, int ntgts) | |
34dc7c2f BB |
532 | { |
533 | uint64_t *dst, *src, xcount, ccount, count, i; | |
45d1cae3 | 534 | int x = tgts[0]; |
34dc7c2f BB |
535 | int c; |
536 | ||
45d1cae3 BB |
537 | ASSERT(ntgts == 1); |
538 | ASSERT(x >= rm->rm_firstdatacol); | |
539 | ASSERT(x < rm->rm_cols); | |
540 | ||
34dc7c2f BB |
541 | xcount = rm->rm_col[x].rc_size / sizeof (src[0]); |
542 | ASSERT(xcount <= rm->rm_col[VDEV_RAIDZ_P].rc_size / sizeof (src[0])); | |
543 | ASSERT(xcount > 0); | |
544 | ||
545 | src = rm->rm_col[VDEV_RAIDZ_P].rc_data; | |
546 | dst = rm->rm_col[x].rc_data; | |
547 | for (i = 0; i < xcount; i++, dst++, src++) { | |
548 | *dst = *src; | |
549 | } | |
550 | ||
551 | for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { | |
552 | src = rm->rm_col[c].rc_data; | |
553 | dst = rm->rm_col[x].rc_data; | |
554 | ||
555 | if (c == x) | |
556 | continue; | |
557 | ||
558 | ccount = rm->rm_col[c].rc_size / sizeof (src[0]); | |
559 | count = MIN(ccount, xcount); | |
560 | ||
561 | for (i = 0; i < count; i++, dst++, src++) { | |
562 | *dst ^= *src; | |
563 | } | |
564 | } | |
45d1cae3 BB |
565 | |
566 | return (1 << VDEV_RAIDZ_P); | |
34dc7c2f BB |
567 | } |
568 | ||
45d1cae3 BB |
569 | static int |
570 | vdev_raidz_reconstruct_q(raidz_map_t *rm, int *tgts, int ntgts) | |
34dc7c2f BB |
571 | { |
572 | uint64_t *dst, *src, xcount, ccount, count, mask, i; | |
573 | uint8_t *b; | |
45d1cae3 | 574 | int x = tgts[0]; |
34dc7c2f BB |
575 | int c, j, exp; |
576 | ||
45d1cae3 BB |
577 | ASSERT(ntgts == 1); |
578 | ||
34dc7c2f BB |
579 | xcount = rm->rm_col[x].rc_size / sizeof (src[0]); |
580 | ASSERT(xcount <= rm->rm_col[VDEV_RAIDZ_Q].rc_size / sizeof (src[0])); | |
581 | ||
582 | for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { | |
583 | src = rm->rm_col[c].rc_data; | |
584 | dst = rm->rm_col[x].rc_data; | |
585 | ||
586 | if (c == x) | |
587 | ccount = 0; | |
588 | else | |
589 | ccount = rm->rm_col[c].rc_size / sizeof (src[0]); | |
590 | ||
591 | count = MIN(ccount, xcount); | |
592 | ||
593 | if (c == rm->rm_firstdatacol) { | |
594 | for (i = 0; i < count; i++, dst++, src++) { | |
595 | *dst = *src; | |
596 | } | |
597 | for (; i < xcount; i++, dst++) { | |
598 | *dst = 0; | |
599 | } | |
600 | ||
601 | } else { | |
34dc7c2f | 602 | for (i = 0; i < count; i++, dst++, src++) { |
45d1cae3 | 603 | VDEV_RAIDZ_64MUL_2(*dst, mask); |
34dc7c2f BB |
604 | *dst ^= *src; |
605 | } | |
606 | ||
607 | for (; i < xcount; i++, dst++) { | |
45d1cae3 | 608 | VDEV_RAIDZ_64MUL_2(*dst, mask); |
34dc7c2f BB |
609 | } |
610 | } | |
611 | } | |
612 | ||
613 | src = rm->rm_col[VDEV_RAIDZ_Q].rc_data; | |
614 | dst = rm->rm_col[x].rc_data; | |
615 | exp = 255 - (rm->rm_cols - 1 - x); | |
616 | ||
617 | for (i = 0; i < xcount; i++, dst++, src++) { | |
618 | *dst ^= *src; | |
619 | for (j = 0, b = (uint8_t *)dst; j < 8; j++, b++) { | |
620 | *b = vdev_raidz_exp2(*b, exp); | |
621 | } | |
622 | } | |
45d1cae3 BB |
623 | |
624 | return (1 << VDEV_RAIDZ_Q); | |
34dc7c2f BB |
625 | } |
626 | ||
45d1cae3 BB |
627 | static int |
628 | vdev_raidz_reconstruct_pq(raidz_map_t *rm, int *tgts, int ntgts) | |
34dc7c2f BB |
629 | { |
630 | uint8_t *p, *q, *pxy, *qxy, *xd, *yd, tmp, a, b, aexp, bexp; | |
631 | void *pdata, *qdata; | |
632 | uint64_t xsize, ysize, i; | |
45d1cae3 BB |
633 | int x = tgts[0]; |
634 | int y = tgts[1]; | |
34dc7c2f | 635 | |
45d1cae3 | 636 | ASSERT(ntgts == 2); |
34dc7c2f BB |
637 | ASSERT(x < y); |
638 | ASSERT(x >= rm->rm_firstdatacol); | |
639 | ASSERT(y < rm->rm_cols); | |
640 | ||
641 | ASSERT(rm->rm_col[x].rc_size >= rm->rm_col[y].rc_size); | |
642 | ||
643 | /* | |
644 | * Move the parity data aside -- we're going to compute parity as | |
645 | * though columns x and y were full of zeros -- Pxy and Qxy. We want to | |
646 | * reuse the parity generation mechanism without trashing the actual | |
647 | * parity so we make those columns appear to be full of zeros by | |
648 | * setting their lengths to zero. | |
649 | */ | |
650 | pdata = rm->rm_col[VDEV_RAIDZ_P].rc_data; | |
651 | qdata = rm->rm_col[VDEV_RAIDZ_Q].rc_data; | |
652 | xsize = rm->rm_col[x].rc_size; | |
653 | ysize = rm->rm_col[y].rc_size; | |
654 | ||
655 | rm->rm_col[VDEV_RAIDZ_P].rc_data = | |
656 | zio_buf_alloc(rm->rm_col[VDEV_RAIDZ_P].rc_size); | |
657 | rm->rm_col[VDEV_RAIDZ_Q].rc_data = | |
658 | zio_buf_alloc(rm->rm_col[VDEV_RAIDZ_Q].rc_size); | |
659 | rm->rm_col[x].rc_size = 0; | |
660 | rm->rm_col[y].rc_size = 0; | |
661 | ||
662 | vdev_raidz_generate_parity_pq(rm); | |
663 | ||
664 | rm->rm_col[x].rc_size = xsize; | |
665 | rm->rm_col[y].rc_size = ysize; | |
666 | ||
667 | p = pdata; | |
668 | q = qdata; | |
669 | pxy = rm->rm_col[VDEV_RAIDZ_P].rc_data; | |
670 | qxy = rm->rm_col[VDEV_RAIDZ_Q].rc_data; | |
671 | xd = rm->rm_col[x].rc_data; | |
672 | yd = rm->rm_col[y].rc_data; | |
673 | ||
674 | /* | |
675 | * We now have: | |
676 | * Pxy = P + D_x + D_y | |
677 | * Qxy = Q + 2^(ndevs - 1 - x) * D_x + 2^(ndevs - 1 - y) * D_y | |
678 | * | |
679 | * We can then solve for D_x: | |
680 | * D_x = A * (P + Pxy) + B * (Q + Qxy) | |
681 | * where | |
682 | * A = 2^(x - y) * (2^(x - y) + 1)^-1 | |
683 | * B = 2^(ndevs - 1 - x) * (2^(x - y) + 1)^-1 | |
684 | * | |
685 | * With D_x in hand, we can easily solve for D_y: | |
686 | * D_y = P + Pxy + D_x | |
687 | */ | |
688 | ||
689 | a = vdev_raidz_pow2[255 + x - y]; | |
690 | b = vdev_raidz_pow2[255 - (rm->rm_cols - 1 - x)]; | |
691 | tmp = 255 - vdev_raidz_log2[a ^ 1]; | |
692 | ||
693 | aexp = vdev_raidz_log2[vdev_raidz_exp2(a, tmp)]; | |
694 | bexp = vdev_raidz_log2[vdev_raidz_exp2(b, tmp)]; | |
695 | ||
696 | for (i = 0; i < xsize; i++, p++, q++, pxy++, qxy++, xd++, yd++) { | |
697 | *xd = vdev_raidz_exp2(*p ^ *pxy, aexp) ^ | |
698 | vdev_raidz_exp2(*q ^ *qxy, bexp); | |
699 | ||
700 | if (i < ysize) | |
701 | *yd = *p ^ *pxy ^ *xd; | |
702 | } | |
703 | ||
704 | zio_buf_free(rm->rm_col[VDEV_RAIDZ_P].rc_data, | |
705 | rm->rm_col[VDEV_RAIDZ_P].rc_size); | |
706 | zio_buf_free(rm->rm_col[VDEV_RAIDZ_Q].rc_data, | |
707 | rm->rm_col[VDEV_RAIDZ_Q].rc_size); | |
708 | ||
709 | /* | |
710 | * Restore the saved parity data. | |
711 | */ | |
712 | rm->rm_col[VDEV_RAIDZ_P].rc_data = pdata; | |
713 | rm->rm_col[VDEV_RAIDZ_Q].rc_data = qdata; | |
45d1cae3 BB |
714 | |
715 | return ((1 << VDEV_RAIDZ_P) | (1 << VDEV_RAIDZ_Q)); | |
716 | } | |
717 | ||
718 | /* BEGIN CSTYLED */ | |
719 | /* | |
720 | * In the general case of reconstruction, we must solve the system of linear | |
721 | * equations defined by the coeffecients used to generate parity as well as | |
722 | * the contents of the data and parity disks. This can be expressed with | |
723 | * vectors for the original data (D) and the actual data (d) and parity (p) | |
724 | * and a matrix composed of the identity matrix (I) and a dispersal matrix (V): | |
725 | * | |
726 | * __ __ __ __ | |
727 | * | | __ __ | p_0 | | |
728 | * | V | | D_0 | | p_m-1 | | |
729 | * | | x | : | = | d_0 | | |
730 | * | I | | D_n-1 | | : | | |
731 | * | | ~~ ~~ | d_n-1 | | |
732 | * ~~ ~~ ~~ ~~ | |
733 | * | |
734 | * I is simply a square identity matrix of size n, and V is a vandermonde | |
735 | * matrix defined by the coeffecients we chose for the various parity columns | |
736 | * (1, 2, 4). Note that these values were chosen both for simplicity, speedy | |
737 | * computation as well as linear separability. | |
738 | * | |
739 | * __ __ __ __ | |
740 | * | 1 .. 1 1 1 | | p_0 | | |
741 | * | 2^n-1 .. 4 2 1 | __ __ | : | | |
742 | * | 4^n-1 .. 16 4 1 | | D_0 | | p_m-1 | | |
743 | * | 1 .. 0 0 0 | | D_1 | | d_0 | | |
744 | * | 0 .. 0 0 0 | x | D_2 | = | d_1 | | |
745 | * | : : : : | | : | | d_2 | | |
746 | * | 0 .. 1 0 0 | | D_n-1 | | : | | |
747 | * | 0 .. 0 1 0 | ~~ ~~ | : | | |
748 | * | 0 .. 0 0 1 | | d_n-1 | | |
749 | * ~~ ~~ ~~ ~~ | |
750 | * | |
751 | * Note that I, V, d, and p are known. To compute D, we must invert the | |
752 | * matrix and use the known data and parity values to reconstruct the unknown | |
753 | * data values. We begin by removing the rows in V|I and d|p that correspond | |
754 | * to failed or missing columns; we then make V|I square (n x n) and d|p | |
755 | * sized n by removing rows corresponding to unused parity from the bottom up | |
756 | * to generate (V|I)' and (d|p)'. We can then generate the inverse of (V|I)' | |
757 | * using Gauss-Jordan elimination. In the example below we use m=3 parity | |
758 | * columns, n=8 data columns, with errors in d_1, d_2, and p_1: | |
759 | * __ __ | |
760 | * | 1 1 1 1 1 1 1 1 | | |
761 | * | 128 64 32 16 8 4 2 1 | <-----+-+-- missing disks | |
762 | * | 19 205 116 29 64 16 4 1 | / / | |
763 | * | 1 0 0 0 0 0 0 0 | / / | |
764 | * | 0 1 0 0 0 0 0 0 | <--' / | |
765 | * (V|I) = | 0 0 1 0 0 0 0 0 | <---' | |
766 | * | 0 0 0 1 0 0 0 0 | | |
767 | * | 0 0 0 0 1 0 0 0 | | |
768 | * | 0 0 0 0 0 1 0 0 | | |
769 | * | 0 0 0 0 0 0 1 0 | | |
770 | * | 0 0 0 0 0 0 0 1 | | |
771 | * ~~ ~~ | |
772 | * __ __ | |
773 | * | 1 1 1 1 1 1 1 1 | | |
774 | * | 128 64 32 16 8 4 2 1 | | |
775 | * | 19 205 116 29 64 16 4 1 | | |
776 | * | 1 0 0 0 0 0 0 0 | | |
777 | * | 0 1 0 0 0 0 0 0 | | |
778 | * (V|I)' = | 0 0 1 0 0 0 0 0 | | |
779 | * | 0 0 0 1 0 0 0 0 | | |
780 | * | 0 0 0 0 1 0 0 0 | | |
781 | * | 0 0 0 0 0 1 0 0 | | |
782 | * | 0 0 0 0 0 0 1 0 | | |
783 | * | 0 0 0 0 0 0 0 1 | | |
784 | * ~~ ~~ | |
785 | * | |
786 | * Here we employ Gauss-Jordan elimination to find the inverse of (V|I)'. We | |
787 | * have carefully chosen the seed values 1, 2, and 4 to ensure that this | |
788 | * matrix is not singular. | |
789 | * __ __ | |
790 | * | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 | | |
791 | * | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 | | |
792 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | | |
793 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | | |
794 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | | |
795 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | | |
796 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | | |
797 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | | |
798 | * ~~ ~~ | |
799 | * __ __ | |
800 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | | |
801 | * | 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 | | |
802 | * | 19 205 116 29 64 16 4 1 0 1 0 0 0 0 0 0 | | |
803 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | | |
804 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | | |
805 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | | |
806 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | | |
807 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | | |
808 | * ~~ ~~ | |
809 | * __ __ | |
810 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | | |
811 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | | |
812 | * | 0 205 116 0 0 0 0 0 0 1 19 29 64 16 4 1 | | |
813 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | | |
814 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | | |
815 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | | |
816 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | | |
817 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | | |
818 | * ~~ ~~ | |
819 | * __ __ | |
820 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | | |
821 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | | |
822 | * | 0 0 185 0 0 0 0 0 205 1 222 208 141 221 201 204 | | |
823 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | | |
824 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | | |
825 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | | |
826 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | | |
827 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | | |
828 | * ~~ ~~ | |
829 | * __ __ | |
830 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | | |
831 | * | 0 1 1 0 0 0 0 0 1 0 1 1 1 1 1 1 | | |
832 | * | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 | | |
833 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | | |
834 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | | |
835 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | | |
836 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | | |
837 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | | |
838 | * ~~ ~~ | |
839 | * __ __ | |
840 | * | 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 | | |
841 | * | 0 1 0 0 0 0 0 0 167 100 5 41 159 169 217 208 | | |
842 | * | 0 0 1 0 0 0 0 0 166 100 4 40 158 168 216 209 | | |
843 | * | 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 | | |
844 | * | 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 0 | | |
845 | * | 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 0 | | |
846 | * | 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 0 | | |
847 | * | 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 | | |
848 | * ~~ ~~ | |
849 | * __ __ | |
850 | * | 0 0 1 0 0 0 0 0 | | |
851 | * | 167 100 5 41 159 169 217 208 | | |
852 | * | 166 100 4 40 158 168 216 209 | | |
853 | * (V|I)'^-1 = | 0 0 0 1 0 0 0 0 | | |
854 | * | 0 0 0 0 1 0 0 0 | | |
855 | * | 0 0 0 0 0 1 0 0 | | |
856 | * | 0 0 0 0 0 0 1 0 | | |
857 | * | 0 0 0 0 0 0 0 1 | | |
858 | * ~~ ~~ | |
859 | * | |
860 | * We can then simply compute D = (V|I)'^-1 x (d|p)' to discover the values | |
861 | * of the missing data. | |
862 | * | |
863 | * As is apparent from the example above, the only non-trivial rows in the | |
864 | * inverse matrix correspond to the data disks that we're trying to | |
865 | * reconstruct. Indeed, those are the only rows we need as the others would | |
866 | * only be useful for reconstructing data known or assumed to be valid. For | |
867 | * that reason, we only build the coefficients in the rows that correspond to | |
868 | * targeted columns. | |
869 | */ | |
870 | /* END CSTYLED */ | |
871 | ||
872 | static void | |
873 | vdev_raidz_matrix_init(raidz_map_t *rm, int n, int nmap, int *map, | |
874 | uint8_t **rows) | |
875 | { | |
876 | int i, j; | |
877 | int pow; | |
878 | ||
879 | ASSERT(n == rm->rm_cols - rm->rm_firstdatacol); | |
880 | ||
881 | /* | |
882 | * Fill in the missing rows of interest. | |
883 | */ | |
884 | for (i = 0; i < nmap; i++) { | |
885 | ASSERT3S(0, <=, map[i]); | |
886 | ASSERT3S(map[i], <=, 2); | |
887 | ||
888 | pow = map[i] * n; | |
889 | if (pow > 255) | |
890 | pow -= 255; | |
891 | ASSERT(pow <= 255); | |
892 | ||
893 | for (j = 0; j < n; j++) { | |
894 | pow -= map[i]; | |
895 | if (pow < 0) | |
896 | pow += 255; | |
897 | rows[i][j] = vdev_raidz_pow2[pow]; | |
898 | } | |
899 | } | |
900 | } | |
901 | ||
902 | static void | |
903 | vdev_raidz_matrix_invert(raidz_map_t *rm, int n, int nmissing, int *missing, | |
904 | uint8_t **rows, uint8_t **invrows, const uint8_t *used) | |
905 | { | |
906 | int i, j, ii, jj; | |
907 | uint8_t log; | |
908 | ||
909 | /* | |
910 | * Assert that the first nmissing entries from the array of used | |
911 | * columns correspond to parity columns and that subsequent entries | |
912 | * correspond to data columns. | |
913 | */ | |
914 | for (i = 0; i < nmissing; i++) { | |
915 | ASSERT3S(used[i], <, rm->rm_firstdatacol); | |
916 | } | |
917 | for (; i < n; i++) { | |
918 | ASSERT3S(used[i], >=, rm->rm_firstdatacol); | |
919 | } | |
920 | ||
921 | /* | |
922 | * First initialize the storage where we'll compute the inverse rows. | |
923 | */ | |
924 | for (i = 0; i < nmissing; i++) { | |
925 | for (j = 0; j < n; j++) { | |
926 | invrows[i][j] = (i == j) ? 1 : 0; | |
927 | } | |
928 | } | |
929 | ||
930 | /* | |
931 | * Subtract all trivial rows from the rows of consequence. | |
932 | */ | |
933 | for (i = 0; i < nmissing; i++) { | |
934 | for (j = nmissing; j < n; j++) { | |
935 | ASSERT3U(used[j], >=, rm->rm_firstdatacol); | |
936 | jj = used[j] - rm->rm_firstdatacol; | |
937 | ASSERT3S(jj, <, n); | |
938 | invrows[i][j] = rows[i][jj]; | |
939 | rows[i][jj] = 0; | |
940 | } | |
941 | } | |
942 | ||
943 | /* | |
944 | * For each of the rows of interest, we must normalize it and subtract | |
945 | * a multiple of it from the other rows. | |
946 | */ | |
947 | for (i = 0; i < nmissing; i++) { | |
948 | for (j = 0; j < missing[i]; j++) { | |
949 | ASSERT3U(rows[i][j], ==, 0); | |
950 | } | |
951 | ASSERT3U(rows[i][missing[i]], !=, 0); | |
952 | ||
953 | /* | |
954 | * Compute the inverse of the first element and multiply each | |
955 | * element in the row by that value. | |
956 | */ | |
957 | log = 255 - vdev_raidz_log2[rows[i][missing[i]]]; | |
958 | ||
959 | for (j = 0; j < n; j++) { | |
960 | rows[i][j] = vdev_raidz_exp2(rows[i][j], log); | |
961 | invrows[i][j] = vdev_raidz_exp2(invrows[i][j], log); | |
962 | } | |
963 | ||
964 | for (ii = 0; ii < nmissing; ii++) { | |
965 | if (i == ii) | |
966 | continue; | |
967 | ||
968 | ASSERT3U(rows[ii][missing[i]], !=, 0); | |
969 | ||
970 | log = vdev_raidz_log2[rows[ii][missing[i]]]; | |
971 | ||
972 | for (j = 0; j < n; j++) { | |
973 | rows[ii][j] ^= | |
974 | vdev_raidz_exp2(rows[i][j], log); | |
975 | invrows[ii][j] ^= | |
976 | vdev_raidz_exp2(invrows[i][j], log); | |
977 | } | |
978 | } | |
979 | } | |
980 | ||
981 | /* | |
982 | * Verify that the data that is left in the rows are properly part of | |
983 | * an identity matrix. | |
984 | */ | |
985 | for (i = 0; i < nmissing; i++) { | |
986 | for (j = 0; j < n; j++) { | |
987 | if (j == missing[i]) { | |
988 | ASSERT3U(rows[i][j], ==, 1); | |
989 | } else { | |
990 | ASSERT3U(rows[i][j], ==, 0); | |
991 | } | |
992 | } | |
993 | } | |
994 | } | |
995 | ||
996 | static void | |
997 | vdev_raidz_matrix_reconstruct(raidz_map_t *rm, int n, int nmissing, | |
998 | int *missing, uint8_t **invrows, const uint8_t *used) | |
999 | { | |
1000 | int i, j, x, cc, c; | |
1001 | uint8_t *src; | |
1002 | uint64_t ccount; | |
1003 | uint8_t *dst[VDEV_RAIDZ_MAXPARITY]; | |
1004 | uint64_t dcount[VDEV_RAIDZ_MAXPARITY]; | |
1005 | uint8_t log, val; | |
1006 | int ll; | |
1007 | uint8_t *invlog[VDEV_RAIDZ_MAXPARITY]; | |
1008 | uint8_t *p, *pp; | |
1009 | size_t psize; | |
1010 | ||
1011 | psize = sizeof (invlog[0][0]) * n * nmissing; | |
1012 | p = kmem_alloc(psize, KM_SLEEP); | |
1013 | ||
1014 | for (pp = p, i = 0; i < nmissing; i++) { | |
1015 | invlog[i] = pp; | |
1016 | pp += n; | |
1017 | } | |
1018 | ||
1019 | for (i = 0; i < nmissing; i++) { | |
1020 | for (j = 0; j < n; j++) { | |
1021 | ASSERT3U(invrows[i][j], !=, 0); | |
1022 | invlog[i][j] = vdev_raidz_log2[invrows[i][j]]; | |
1023 | } | |
1024 | } | |
1025 | ||
1026 | for (i = 0; i < n; i++) { | |
1027 | c = used[i]; | |
1028 | ASSERT3U(c, <, rm->rm_cols); | |
1029 | ||
1030 | src = rm->rm_col[c].rc_data; | |
1031 | ccount = rm->rm_col[c].rc_size; | |
1032 | for (j = 0; j < nmissing; j++) { | |
1033 | cc = missing[j] + rm->rm_firstdatacol; | |
1034 | ASSERT3U(cc, >=, rm->rm_firstdatacol); | |
1035 | ASSERT3U(cc, <, rm->rm_cols); | |
1036 | ASSERT3U(cc, !=, c); | |
1037 | ||
1038 | dst[j] = rm->rm_col[cc].rc_data; | |
1039 | dcount[j] = rm->rm_col[cc].rc_size; | |
1040 | } | |
1041 | ||
1042 | ASSERT(ccount >= rm->rm_col[missing[0]].rc_size || i > 0); | |
1043 | ||
1044 | for (x = 0; x < ccount; x++, src++) { | |
1045 | if (*src != 0) | |
1046 | log = vdev_raidz_log2[*src]; | |
1047 | ||
1048 | for (cc = 0; cc < nmissing; cc++) { | |
1049 | if (x >= dcount[cc]) | |
1050 | continue; | |
1051 | ||
1052 | if (*src == 0) { | |
1053 | val = 0; | |
1054 | } else { | |
1055 | if ((ll = log + invlog[cc][i]) >= 255) | |
1056 | ll -= 255; | |
1057 | val = vdev_raidz_pow2[ll]; | |
1058 | } | |
1059 | ||
1060 | if (i == 0) | |
1061 | dst[cc][x] = val; | |
1062 | else | |
1063 | dst[cc][x] ^= val; | |
1064 | } | |
1065 | } | |
1066 | } | |
1067 | ||
1068 | kmem_free(p, psize); | |
1069 | } | |
1070 | ||
1071 | static int | |
1072 | vdev_raidz_reconstruct_general(raidz_map_t *rm, int *tgts, int ntgts) | |
1073 | { | |
1074 | int n, i, c, t, tt; | |
1075 | int nmissing_rows; | |
1076 | int missing_rows[VDEV_RAIDZ_MAXPARITY]; | |
1077 | int parity_map[VDEV_RAIDZ_MAXPARITY]; | |
1078 | ||
1079 | uint8_t *p, *pp; | |
1080 | size_t psize; | |
1081 | ||
1082 | uint8_t *rows[VDEV_RAIDZ_MAXPARITY]; | |
1083 | uint8_t *invrows[VDEV_RAIDZ_MAXPARITY]; | |
1084 | uint8_t *used; | |
1085 | ||
1086 | int code = 0; | |
1087 | ||
1088 | ||
1089 | n = rm->rm_cols - rm->rm_firstdatacol; | |
1090 | ||
1091 | /* | |
1092 | * Figure out which data columns are missing. | |
1093 | */ | |
1094 | nmissing_rows = 0; | |
1095 | for (t = 0; t < ntgts; t++) { | |
1096 | if (tgts[t] >= rm->rm_firstdatacol) { | |
1097 | missing_rows[nmissing_rows++] = | |
1098 | tgts[t] - rm->rm_firstdatacol; | |
1099 | } | |
1100 | } | |
1101 | ||
1102 | /* | |
1103 | * Figure out which parity columns to use to help generate the missing | |
1104 | * data columns. | |
1105 | */ | |
1106 | for (tt = 0, c = 0, i = 0; i < nmissing_rows; c++) { | |
1107 | ASSERT(tt < ntgts); | |
1108 | ASSERT(c < rm->rm_firstdatacol); | |
1109 | ||
1110 | /* | |
1111 | * Skip any targeted parity columns. | |
1112 | */ | |
1113 | if (c == tgts[tt]) { | |
1114 | tt++; | |
1115 | continue; | |
1116 | } | |
1117 | ||
1118 | code |= 1 << c; | |
1119 | ||
1120 | parity_map[i] = c; | |
1121 | i++; | |
1122 | } | |
1123 | ||
1124 | ASSERT(code != 0); | |
1125 | ASSERT3U(code, <, 1 << VDEV_RAIDZ_MAXPARITY); | |
1126 | ||
1127 | psize = (sizeof (rows[0][0]) + sizeof (invrows[0][0])) * | |
1128 | nmissing_rows * n + sizeof (used[0]) * n; | |
1129 | p = kmem_alloc(psize, KM_SLEEP); | |
1130 | ||
1131 | for (pp = p, i = 0; i < nmissing_rows; i++) { | |
1132 | rows[i] = pp; | |
1133 | pp += n; | |
1134 | invrows[i] = pp; | |
1135 | pp += n; | |
1136 | } | |
1137 | used = pp; | |
1138 | ||
1139 | for (i = 0; i < nmissing_rows; i++) { | |
1140 | used[i] = parity_map[i]; | |
1141 | } | |
1142 | ||
1143 | for (tt = 0, c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { | |
1144 | if (tt < nmissing_rows && | |
1145 | c == missing_rows[tt] + rm->rm_firstdatacol) { | |
1146 | tt++; | |
1147 | continue; | |
1148 | } | |
1149 | ||
1150 | ASSERT3S(i, <, n); | |
1151 | used[i] = c; | |
1152 | i++; | |
1153 | } | |
1154 | ||
1155 | /* | |
1156 | * Initialize the interesting rows of the matrix. | |
1157 | */ | |
1158 | vdev_raidz_matrix_init(rm, n, nmissing_rows, parity_map, rows); | |
1159 | ||
1160 | /* | |
1161 | * Invert the matrix. | |
1162 | */ | |
1163 | vdev_raidz_matrix_invert(rm, n, nmissing_rows, missing_rows, rows, | |
1164 | invrows, used); | |
1165 | ||
1166 | /* | |
1167 | * Reconstruct the missing data using the generated matrix. | |
1168 | */ | |
1169 | vdev_raidz_matrix_reconstruct(rm, n, nmissing_rows, missing_rows, | |
1170 | invrows, used); | |
1171 | ||
1172 | kmem_free(p, psize); | |
1173 | ||
1174 | return (code); | |
34dc7c2f BB |
1175 | } |
1176 | ||
45d1cae3 BB |
1177 | static int |
1178 | vdev_raidz_reconstruct(raidz_map_t *rm, int *t, int nt) | |
1179 | { | |
1180 | int tgts[VDEV_RAIDZ_MAXPARITY], *dt; | |
1181 | int ntgts; | |
1182 | int i, c; | |
1183 | int code; | |
1184 | int nbadparity, nbaddata; | |
1185 | int parity_valid[VDEV_RAIDZ_MAXPARITY]; | |
1186 | ||
1187 | /* | |
1188 | * The tgts list must already be sorted. | |
1189 | */ | |
1190 | for (i = 1; i < nt; i++) { | |
1191 | ASSERT(t[i] > t[i - 1]); | |
1192 | } | |
1193 | ||
1194 | nbadparity = rm->rm_firstdatacol; | |
1195 | nbaddata = rm->rm_cols - nbadparity; | |
1196 | ntgts = 0; | |
1197 | for (i = 0, c = 0; c < rm->rm_cols; c++) { | |
1198 | if (c < rm->rm_firstdatacol) | |
1199 | parity_valid[c] = B_FALSE; | |
1200 | ||
1201 | if (i < nt && c == t[i]) { | |
1202 | tgts[ntgts++] = c; | |
1203 | i++; | |
1204 | } else if (rm->rm_col[c].rc_error != 0) { | |
1205 | tgts[ntgts++] = c; | |
1206 | } else if (c >= rm->rm_firstdatacol) { | |
1207 | nbaddata--; | |
1208 | } else { | |
1209 | parity_valid[c] = B_TRUE; | |
1210 | nbadparity--; | |
1211 | } | |
1212 | } | |
1213 | ||
1214 | ASSERT(ntgts >= nt); | |
1215 | ASSERT(nbaddata >= 0); | |
1216 | ASSERT(nbaddata + nbadparity == ntgts); | |
1217 | ||
1218 | dt = &tgts[nbadparity]; | |
1219 | ||
1220 | /* | |
1221 | * See if we can use any of our optimized reconstruction routines. | |
1222 | */ | |
1223 | if (!vdev_raidz_default_to_general) { | |
1224 | switch (nbaddata) { | |
1225 | case 1: | |
1226 | if (parity_valid[VDEV_RAIDZ_P]) | |
1227 | return (vdev_raidz_reconstruct_p(rm, dt, 1)); | |
1228 | ||
1229 | ASSERT(rm->rm_firstdatacol > 1); | |
1230 | ||
1231 | if (parity_valid[VDEV_RAIDZ_Q]) | |
1232 | return (vdev_raidz_reconstruct_q(rm, dt, 1)); | |
1233 | ||
1234 | ASSERT(rm->rm_firstdatacol > 2); | |
1235 | break; | |
1236 | ||
1237 | case 2: | |
1238 | ASSERT(rm->rm_firstdatacol > 1); | |
1239 | ||
1240 | if (parity_valid[VDEV_RAIDZ_P] && | |
1241 | parity_valid[VDEV_RAIDZ_Q]) | |
1242 | return (vdev_raidz_reconstruct_pq(rm, dt, 2)); | |
1243 | ||
1244 | ASSERT(rm->rm_firstdatacol > 2); | |
1245 | ||
1246 | break; | |
1247 | } | |
1248 | } | |
1249 | ||
1250 | code = vdev_raidz_reconstruct_general(rm, tgts, ntgts); | |
1251 | ASSERT(code < (1 << VDEV_RAIDZ_MAXPARITY)); | |
1252 | ASSERT(code > 0); | |
1253 | return (code); | |
1254 | } | |
34dc7c2f BB |
1255 | |
1256 | static int | |
1257 | vdev_raidz_open(vdev_t *vd, uint64_t *asize, uint64_t *ashift) | |
1258 | { | |
1259 | vdev_t *cvd; | |
1260 | uint64_t nparity = vd->vdev_nparity; | |
45d1cae3 | 1261 | int c; |
34dc7c2f BB |
1262 | int lasterror = 0; |
1263 | int numerrors = 0; | |
1264 | ||
1265 | ASSERT(nparity > 0); | |
1266 | ||
1267 | if (nparity > VDEV_RAIDZ_MAXPARITY || | |
1268 | vd->vdev_children < nparity + 1) { | |
1269 | vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL; | |
1270 | return (EINVAL); | |
1271 | } | |
1272 | ||
45d1cae3 BB |
1273 | vdev_open_children(vd); |
1274 | ||
34dc7c2f BB |
1275 | for (c = 0; c < vd->vdev_children; c++) { |
1276 | cvd = vd->vdev_child[c]; | |
1277 | ||
45d1cae3 BB |
1278 | if (cvd->vdev_open_error != 0) { |
1279 | lasterror = cvd->vdev_open_error; | |
34dc7c2f BB |
1280 | numerrors++; |
1281 | continue; | |
1282 | } | |
1283 | ||
1284 | *asize = MIN(*asize - 1, cvd->vdev_asize - 1) + 1; | |
1285 | *ashift = MAX(*ashift, cvd->vdev_ashift); | |
1286 | } | |
1287 | ||
1288 | *asize *= vd->vdev_children; | |
1289 | ||
1290 | if (numerrors > nparity) { | |
1291 | vd->vdev_stat.vs_aux = VDEV_AUX_NO_REPLICAS; | |
1292 | return (lasterror); | |
1293 | } | |
1294 | ||
1295 | return (0); | |
1296 | } | |
1297 | ||
1298 | static void | |
1299 | vdev_raidz_close(vdev_t *vd) | |
1300 | { | |
1301 | int c; | |
1302 | ||
1303 | for (c = 0; c < vd->vdev_children; c++) | |
1304 | vdev_close(vd->vdev_child[c]); | |
1305 | } | |
1306 | ||
1307 | static uint64_t | |
1308 | vdev_raidz_asize(vdev_t *vd, uint64_t psize) | |
1309 | { | |
1310 | uint64_t asize; | |
1311 | uint64_t ashift = vd->vdev_top->vdev_ashift; | |
1312 | uint64_t cols = vd->vdev_children; | |
1313 | uint64_t nparity = vd->vdev_nparity; | |
1314 | ||
1315 | asize = ((psize - 1) >> ashift) + 1; | |
1316 | asize += nparity * ((asize + cols - nparity - 1) / (cols - nparity)); | |
1317 | asize = roundup(asize, nparity + 1) << ashift; | |
1318 | ||
1319 | return (asize); | |
1320 | } | |
1321 | ||
1322 | static void | |
1323 | vdev_raidz_child_done(zio_t *zio) | |
1324 | { | |
1325 | raidz_col_t *rc = zio->io_private; | |
1326 | ||
1327 | rc->rc_error = zio->io_error; | |
1328 | rc->rc_tried = 1; | |
1329 | rc->rc_skipped = 0; | |
1330 | } | |
1331 | ||
34dc7c2f BB |
1332 | static int |
1333 | vdev_raidz_io_start(zio_t *zio) | |
1334 | { | |
1335 | vdev_t *vd = zio->io_vd; | |
1336 | vdev_t *tvd = vd->vdev_top; | |
1337 | vdev_t *cvd; | |
1338 | blkptr_t *bp = zio->io_bp; | |
1339 | raidz_map_t *rm; | |
1340 | raidz_col_t *rc; | |
45d1cae3 | 1341 | int c, i; |
34dc7c2f BB |
1342 | |
1343 | rm = vdev_raidz_map_alloc(zio, tvd->vdev_ashift, vd->vdev_children, | |
1344 | vd->vdev_nparity); | |
1345 | ||
1346 | ASSERT3U(rm->rm_asize, ==, vdev_psize_to_asize(vd, zio->io_size)); | |
1347 | ||
1348 | if (zio->io_type == ZIO_TYPE_WRITE) { | |
45d1cae3 | 1349 | vdev_raidz_generate_parity(rm); |
34dc7c2f BB |
1350 | |
1351 | for (c = 0; c < rm->rm_cols; c++) { | |
1352 | rc = &rm->rm_col[c]; | |
1353 | cvd = vd->vdev_child[rc->rc_devidx]; | |
1354 | zio_nowait(zio_vdev_child_io(zio, NULL, cvd, | |
1355 | rc->rc_offset, rc->rc_data, rc->rc_size, | |
b128c09f | 1356 | zio->io_type, zio->io_priority, 0, |
34dc7c2f BB |
1357 | vdev_raidz_child_done, rc)); |
1358 | } | |
1359 | ||
45d1cae3 BB |
1360 | /* |
1361 | * Generate optional I/Os for any skipped sectors to improve | |
1362 | * aggregation contiguity. | |
1363 | */ | |
1364 | for (c = rm->rm_bigcols, i = 0; i < rm->rm_skipped; c++, i++) { | |
1365 | ASSERT(c <= rm->rm_scols); | |
1366 | if (c == rm->rm_scols) | |
1367 | c = 0; | |
1368 | rc = &rm->rm_col[c]; | |
1369 | cvd = vd->vdev_child[rc->rc_devidx]; | |
1370 | zio_nowait(zio_vdev_child_io(zio, NULL, cvd, | |
1371 | rc->rc_offset + rc->rc_size, NULL, | |
1372 | 1 << tvd->vdev_ashift, | |
1373 | zio->io_type, zio->io_priority, | |
1374 | ZIO_FLAG_NODATA | ZIO_FLAG_OPTIONAL, NULL, NULL)); | |
1375 | } | |
1376 | ||
b128c09f | 1377 | return (ZIO_PIPELINE_CONTINUE); |
34dc7c2f BB |
1378 | } |
1379 | ||
1380 | ASSERT(zio->io_type == ZIO_TYPE_READ); | |
1381 | ||
1382 | /* | |
1383 | * Iterate over the columns in reverse order so that we hit the parity | |
45d1cae3 | 1384 | * last -- any errors along the way will force us to read the parity. |
34dc7c2f BB |
1385 | */ |
1386 | for (c = rm->rm_cols - 1; c >= 0; c--) { | |
1387 | rc = &rm->rm_col[c]; | |
1388 | cvd = vd->vdev_child[rc->rc_devidx]; | |
1389 | if (!vdev_readable(cvd)) { | |
1390 | if (c >= rm->rm_firstdatacol) | |
1391 | rm->rm_missingdata++; | |
1392 | else | |
1393 | rm->rm_missingparity++; | |
1394 | rc->rc_error = ENXIO; | |
1395 | rc->rc_tried = 1; /* don't even try */ | |
1396 | rc->rc_skipped = 1; | |
1397 | continue; | |
1398 | } | |
fb5f0bc8 | 1399 | if (vdev_dtl_contains(cvd, DTL_MISSING, bp->blk_birth, 1)) { |
34dc7c2f BB |
1400 | if (c >= rm->rm_firstdatacol) |
1401 | rm->rm_missingdata++; | |
1402 | else | |
1403 | rm->rm_missingparity++; | |
1404 | rc->rc_error = ESTALE; | |
1405 | rc->rc_skipped = 1; | |
1406 | continue; | |
1407 | } | |
1408 | if (c >= rm->rm_firstdatacol || rm->rm_missingdata > 0 || | |
9babb374 | 1409 | (zio->io_flags & (ZIO_FLAG_SCRUB | ZIO_FLAG_RESILVER))) { |
34dc7c2f BB |
1410 | zio_nowait(zio_vdev_child_io(zio, NULL, cvd, |
1411 | rc->rc_offset, rc->rc_data, rc->rc_size, | |
b128c09f | 1412 | zio->io_type, zio->io_priority, 0, |
34dc7c2f BB |
1413 | vdev_raidz_child_done, rc)); |
1414 | } | |
1415 | } | |
1416 | ||
b128c09f | 1417 | return (ZIO_PIPELINE_CONTINUE); |
34dc7c2f BB |
1418 | } |
1419 | ||
1420 | /* | |
1421 | * Report a checksum error for a child of a RAID-Z device. | |
1422 | */ | |
1423 | static void | |
1424 | raidz_checksum_error(zio_t *zio, raidz_col_t *rc) | |
1425 | { | |
1426 | vdev_t *vd = zio->io_vd->vdev_child[rc->rc_devidx]; | |
34dc7c2f BB |
1427 | |
1428 | if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { | |
1429 | mutex_enter(&vd->vdev_stat_lock); | |
1430 | vd->vdev_stat.vs_checksum_errors++; | |
1431 | mutex_exit(&vd->vdev_stat_lock); | |
1432 | } | |
1433 | ||
1434 | if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) | |
1435 | zfs_ereport_post(FM_EREPORT_ZFS_CHECKSUM, | |
1436 | zio->io_spa, vd, zio, rc->rc_offset, rc->rc_size); | |
1437 | } | |
1438 | ||
1439 | /* | |
1440 | * Generate the parity from the data columns. If we tried and were able to | |
1441 | * read the parity without error, verify that the generated parity matches the | |
1442 | * data we read. If it doesn't, we fire off a checksum error. Return the | |
1443 | * number such failures. | |
1444 | */ | |
1445 | static int | |
1446 | raidz_parity_verify(zio_t *zio, raidz_map_t *rm) | |
1447 | { | |
1448 | void *orig[VDEV_RAIDZ_MAXPARITY]; | |
1449 | int c, ret = 0; | |
1450 | raidz_col_t *rc; | |
1451 | ||
1452 | for (c = 0; c < rm->rm_firstdatacol; c++) { | |
1453 | rc = &rm->rm_col[c]; | |
1454 | if (!rc->rc_tried || rc->rc_error != 0) | |
1455 | continue; | |
1456 | orig[c] = zio_buf_alloc(rc->rc_size); | |
1457 | bcopy(rc->rc_data, orig[c], rc->rc_size); | |
1458 | } | |
1459 | ||
45d1cae3 | 1460 | vdev_raidz_generate_parity(rm); |
34dc7c2f BB |
1461 | |
1462 | for (c = 0; c < rm->rm_firstdatacol; c++) { | |
1463 | rc = &rm->rm_col[c]; | |
1464 | if (!rc->rc_tried || rc->rc_error != 0) | |
1465 | continue; | |
1466 | if (bcmp(orig[c], rc->rc_data, rc->rc_size) != 0) { | |
1467 | raidz_checksum_error(zio, rc); | |
1468 | rc->rc_error = ECKSUM; | |
1469 | ret++; | |
1470 | } | |
1471 | zio_buf_free(orig[c], rc->rc_size); | |
1472 | } | |
1473 | ||
1474 | return (ret); | |
1475 | } | |
1476 | ||
45d1cae3 BB |
1477 | /* |
1478 | * Keep statistics on all the ways that we used parity to correct data. | |
1479 | */ | |
1480 | static uint64_t raidz_corrected[1 << VDEV_RAIDZ_MAXPARITY]; | |
34dc7c2f BB |
1481 | |
1482 | static int | |
b128c09f BB |
1483 | vdev_raidz_worst_error(raidz_map_t *rm) |
1484 | { | |
1485 | int error = 0; | |
1486 | ||
1487 | for (int c = 0; c < rm->rm_cols; c++) | |
1488 | error = zio_worst_error(error, rm->rm_col[c].rc_error); | |
1489 | ||
1490 | return (error); | |
1491 | } | |
1492 | ||
45d1cae3 BB |
1493 | /* |
1494 | * Iterate over all combinations of bad data and attempt a reconstruction. | |
1495 | * Note that the algorithm below is non-optimal because it doesn't take into | |
1496 | * account how reconstruction is actually performed. For example, with | |
1497 | * triple-parity RAID-Z the reconstruction procedure is the same if column 4 | |
1498 | * is targeted as invalid as if columns 1 and 4 are targeted since in both | |
1499 | * cases we'd only use parity information in column 0. | |
1500 | */ | |
1501 | static int | |
1502 | vdev_raidz_combrec(zio_t *zio, int total_errors, int data_errors) | |
1503 | { | |
1504 | raidz_map_t *rm = zio->io_vsd; | |
1505 | raidz_col_t *rc; | |
1506 | void *orig[VDEV_RAIDZ_MAXPARITY]; | |
1507 | int tstore[VDEV_RAIDZ_MAXPARITY + 2]; | |
1508 | int *tgts = &tstore[1]; | |
1509 | int current, next, i, c, n; | |
1510 | int code, ret = 0; | |
1511 | ||
1512 | ASSERT(total_errors < rm->rm_firstdatacol); | |
1513 | ||
1514 | /* | |
1515 | * This simplifies one edge condition. | |
1516 | */ | |
1517 | tgts[-1] = -1; | |
1518 | ||
1519 | for (n = 1; n <= rm->rm_firstdatacol - total_errors; n++) { | |
1520 | /* | |
1521 | * Initialize the targets array by finding the first n columns | |
1522 | * that contain no error. | |
1523 | * | |
1524 | * If there were no data errors, we need to ensure that we're | |
1525 | * always explicitly attempting to reconstruct at least one | |
1526 | * data column. To do this, we simply push the highest target | |
1527 | * up into the data columns. | |
1528 | */ | |
1529 | for (c = 0, i = 0; i < n; i++) { | |
1530 | if (i == n - 1 && data_errors == 0 && | |
1531 | c < rm->rm_firstdatacol) { | |
1532 | c = rm->rm_firstdatacol; | |
1533 | } | |
1534 | ||
1535 | while (rm->rm_col[c].rc_error != 0) { | |
1536 | c++; | |
1537 | ASSERT3S(c, <, rm->rm_cols); | |
1538 | } | |
1539 | ||
1540 | tgts[i] = c++; | |
1541 | } | |
1542 | ||
1543 | /* | |
1544 | * Setting tgts[n] simplifies the other edge condition. | |
1545 | */ | |
1546 | tgts[n] = rm->rm_cols; | |
1547 | ||
1548 | /* | |
1549 | * These buffers were allocated in previous iterations. | |
1550 | */ | |
1551 | for (i = 0; i < n - 1; i++) { | |
1552 | ASSERT(orig[i] != NULL); | |
1553 | } | |
1554 | ||
1555 | orig[n - 1] = zio_buf_alloc(rm->rm_col[0].rc_size); | |
1556 | ||
1557 | current = 0; | |
1558 | next = tgts[current]; | |
1559 | ||
1560 | while (current != n) { | |
1561 | tgts[current] = next; | |
1562 | current = 0; | |
1563 | ||
1564 | /* | |
1565 | * Save off the original data that we're going to | |
1566 | * attempt to reconstruct. | |
1567 | */ | |
1568 | for (i = 0; i < n; i++) { | |
1569 | ASSERT(orig[i] != NULL); | |
1570 | c = tgts[i]; | |
1571 | ASSERT3S(c, >=, 0); | |
1572 | ASSERT3S(c, <, rm->rm_cols); | |
1573 | rc = &rm->rm_col[c]; | |
1574 | bcopy(rc->rc_data, orig[i], rc->rc_size); | |
1575 | } | |
1576 | ||
1577 | /* | |
1578 | * Attempt a reconstruction and exit the outer loop on | |
1579 | * success. | |
1580 | */ | |
1581 | code = vdev_raidz_reconstruct(rm, tgts, n); | |
1582 | if (zio_checksum_error(zio) == 0) { | |
1583 | atomic_inc_64(&raidz_corrected[code]); | |
1584 | ||
1585 | for (i = 0; i < n; i++) { | |
1586 | c = tgts[i]; | |
1587 | rc = &rm->rm_col[c]; | |
1588 | ASSERT(rc->rc_error == 0); | |
1589 | if (rc->rc_tried) | |
1590 | raidz_checksum_error(zio, rc); | |
1591 | rc->rc_error = ECKSUM; | |
1592 | } | |
1593 | ||
1594 | ret = code; | |
1595 | goto done; | |
1596 | } | |
1597 | ||
1598 | /* | |
1599 | * Restore the original data. | |
1600 | */ | |
1601 | for (i = 0; i < n; i++) { | |
1602 | c = tgts[i]; | |
1603 | rc = &rm->rm_col[c]; | |
1604 | bcopy(orig[i], rc->rc_data, rc->rc_size); | |
1605 | } | |
1606 | ||
1607 | do { | |
1608 | /* | |
1609 | * Find the next valid column after the current | |
1610 | * position.. | |
1611 | */ | |
1612 | for (next = tgts[current] + 1; | |
1613 | next < rm->rm_cols && | |
1614 | rm->rm_col[next].rc_error != 0; next++) | |
1615 | continue; | |
1616 | ||
1617 | ASSERT(next <= tgts[current + 1]); | |
1618 | ||
1619 | /* | |
1620 | * If that spot is available, we're done here. | |
1621 | */ | |
1622 | if (next != tgts[current + 1]) | |
1623 | break; | |
1624 | ||
1625 | /* | |
1626 | * Otherwise, find the next valid column after | |
1627 | * the previous position. | |
1628 | */ | |
1629 | for (c = tgts[current - 1] + 1; | |
1630 | rm->rm_col[c].rc_error != 0; c++) | |
1631 | continue; | |
1632 | ||
1633 | tgts[current] = c; | |
1634 | current++; | |
1635 | ||
1636 | } while (current != n); | |
1637 | } | |
1638 | } | |
1639 | n--; | |
1640 | done: | |
1641 | for (i = 0; i < n; i++) { | |
1642 | zio_buf_free(orig[i], rm->rm_col[0].rc_size); | |
1643 | } | |
1644 | ||
1645 | return (ret); | |
1646 | } | |
1647 | ||
b128c09f | 1648 | static void |
34dc7c2f BB |
1649 | vdev_raidz_io_done(zio_t *zio) |
1650 | { | |
1651 | vdev_t *vd = zio->io_vd; | |
1652 | vdev_t *cvd; | |
1653 | raidz_map_t *rm = zio->io_vsd; | |
45d1cae3 | 1654 | raidz_col_t *rc; |
34dc7c2f BB |
1655 | int unexpected_errors = 0; |
1656 | int parity_errors = 0; | |
1657 | int parity_untried = 0; | |
1658 | int data_errors = 0; | |
b128c09f | 1659 | int total_errors = 0; |
45d1cae3 BB |
1660 | int n, c; |
1661 | int tgts[VDEV_RAIDZ_MAXPARITY]; | |
1662 | int code; | |
34dc7c2f BB |
1663 | |
1664 | ASSERT(zio->io_bp != NULL); /* XXX need to add code to enforce this */ | |
1665 | ||
34dc7c2f BB |
1666 | ASSERT(rm->rm_missingparity <= rm->rm_firstdatacol); |
1667 | ASSERT(rm->rm_missingdata <= rm->rm_cols - rm->rm_firstdatacol); | |
1668 | ||
1669 | for (c = 0; c < rm->rm_cols; c++) { | |
1670 | rc = &rm->rm_col[c]; | |
1671 | ||
34dc7c2f | 1672 | if (rc->rc_error) { |
b128c09f | 1673 | ASSERT(rc->rc_error != ECKSUM); /* child has no bp */ |
34dc7c2f BB |
1674 | |
1675 | if (c < rm->rm_firstdatacol) | |
1676 | parity_errors++; | |
1677 | else | |
1678 | data_errors++; | |
1679 | ||
1680 | if (!rc->rc_skipped) | |
1681 | unexpected_errors++; | |
1682 | ||
b128c09f | 1683 | total_errors++; |
34dc7c2f BB |
1684 | } else if (c < rm->rm_firstdatacol && !rc->rc_tried) { |
1685 | parity_untried++; | |
1686 | } | |
1687 | } | |
1688 | ||
1689 | if (zio->io_type == ZIO_TYPE_WRITE) { | |
1690 | /* | |
b128c09f BB |
1691 | * XXX -- for now, treat partial writes as a success. |
1692 | * (If we couldn't write enough columns to reconstruct | |
1693 | * the data, the I/O failed. Otherwise, good enough.) | |
1694 | * | |
1695 | * Now that we support write reallocation, it would be better | |
1696 | * to treat partial failure as real failure unless there are | |
1697 | * no non-degraded top-level vdevs left, and not update DTLs | |
1698 | * if we intend to reallocate. | |
34dc7c2f BB |
1699 | */ |
1700 | /* XXPOLICY */ | |
b128c09f BB |
1701 | if (total_errors > rm->rm_firstdatacol) |
1702 | zio->io_error = vdev_raidz_worst_error(rm); | |
34dc7c2f | 1703 | |
b128c09f | 1704 | return; |
34dc7c2f BB |
1705 | } |
1706 | ||
1707 | ASSERT(zio->io_type == ZIO_TYPE_READ); | |
1708 | /* | |
1709 | * There are three potential phases for a read: | |
1710 | * 1. produce valid data from the columns read | |
1711 | * 2. read all disks and try again | |
1712 | * 3. perform combinatorial reconstruction | |
1713 | * | |
1714 | * Each phase is progressively both more expensive and less likely to | |
1715 | * occur. If we encounter more errors than we can repair or all phases | |
1716 | * fail, we have no choice but to return an error. | |
1717 | */ | |
1718 | ||
1719 | /* | |
1720 | * If the number of errors we saw was correctable -- less than or equal | |
1721 | * to the number of parity disks read -- attempt to produce data that | |
1722 | * has a valid checksum. Naturally, this case applies in the absence of | |
1723 | * any errors. | |
1724 | */ | |
b128c09f | 1725 | if (total_errors <= rm->rm_firstdatacol - parity_untried) { |
45d1cae3 | 1726 | if (data_errors == 0) { |
34dc7c2f | 1727 | if (zio_checksum_error(zio) == 0) { |
34dc7c2f BB |
1728 | /* |
1729 | * If we read parity information (unnecessarily | |
1730 | * as it happens since no reconstruction was | |
1731 | * needed) regenerate and verify the parity. | |
1732 | * We also regenerate parity when resilvering | |
1733 | * so we can write it out to the failed device | |
1734 | * later. | |
1735 | */ | |
1736 | if (parity_errors + parity_untried < | |
1737 | rm->rm_firstdatacol || | |
1738 | (zio->io_flags & ZIO_FLAG_RESILVER)) { | |
1739 | n = raidz_parity_verify(zio, rm); | |
1740 | unexpected_errors += n; | |
1741 | ASSERT(parity_errors + n <= | |
1742 | rm->rm_firstdatacol); | |
1743 | } | |
1744 | goto done; | |
1745 | } | |
45d1cae3 | 1746 | } else { |
34dc7c2f BB |
1747 | /* |
1748 | * We either attempt to read all the parity columns or | |
1749 | * none of them. If we didn't try to read parity, we | |
1750 | * wouldn't be here in the correctable case. There must | |
1751 | * also have been fewer parity errors than parity | |
1752 | * columns or, again, we wouldn't be in this code path. | |
1753 | */ | |
1754 | ASSERT(parity_untried == 0); | |
1755 | ASSERT(parity_errors < rm->rm_firstdatacol); | |
1756 | ||
1757 | /* | |
45d1cae3 | 1758 | * Identify the data columns that reported an error. |
34dc7c2f | 1759 | */ |
45d1cae3 | 1760 | n = 0; |
34dc7c2f BB |
1761 | for (c = rm->rm_firstdatacol; c < rm->rm_cols; c++) { |
1762 | rc = &rm->rm_col[c]; | |
45d1cae3 BB |
1763 | if (rc->rc_error != 0) { |
1764 | ASSERT(n < VDEV_RAIDZ_MAXPARITY); | |
1765 | tgts[n++] = c; | |
1766 | } | |
34dc7c2f | 1767 | } |
34dc7c2f | 1768 | |
45d1cae3 BB |
1769 | ASSERT(rm->rm_firstdatacol >= n); |
1770 | ||
1771 | code = vdev_raidz_reconstruct(rm, tgts, n); | |
34dc7c2f BB |
1772 | |
1773 | if (zio_checksum_error(zio) == 0) { | |
45d1cae3 | 1774 | atomic_inc_64(&raidz_corrected[code]); |
34dc7c2f BB |
1775 | |
1776 | /* | |
45d1cae3 BB |
1777 | * If we read more parity disks than were used |
1778 | * for reconstruction, confirm that the other | |
1779 | * parity disks produced correct data. This | |
1780 | * routine is suboptimal in that it regenerates | |
1781 | * the parity that we already used in addition | |
1782 | * to the parity that we're attempting to | |
1783 | * verify, but this should be a relatively | |
1784 | * uncommon case, and can be optimized if it | |
1785 | * becomes a problem. Note that we regenerate | |
1786 | * parity when resilvering so we can write it | |
1787 | * out to failed devices later. | |
34dc7c2f | 1788 | */ |
45d1cae3 | 1789 | if (parity_errors < rm->rm_firstdatacol - n || |
34dc7c2f BB |
1790 | (zio->io_flags & ZIO_FLAG_RESILVER)) { |
1791 | n = raidz_parity_verify(zio, rm); | |
1792 | unexpected_errors += n; | |
1793 | ASSERT(parity_errors + n <= | |
1794 | rm->rm_firstdatacol); | |
1795 | } | |
1796 | ||
1797 | goto done; | |
1798 | } | |
34dc7c2f BB |
1799 | } |
1800 | } | |
1801 | ||
1802 | /* | |
1803 | * This isn't a typical situation -- either we got a read error or | |
1804 | * a child silently returned bad data. Read every block so we can | |
1805 | * try again with as much data and parity as we can track down. If | |
1806 | * we've already been through once before, all children will be marked | |
1807 | * as tried so we'll proceed to combinatorial reconstruction. | |
1808 | */ | |
1809 | unexpected_errors = 1; | |
1810 | rm->rm_missingdata = 0; | |
1811 | rm->rm_missingparity = 0; | |
1812 | ||
1813 | for (c = 0; c < rm->rm_cols; c++) { | |
1814 | if (rm->rm_col[c].rc_tried) | |
1815 | continue; | |
1816 | ||
34dc7c2f BB |
1817 | zio_vdev_io_redone(zio); |
1818 | do { | |
1819 | rc = &rm->rm_col[c]; | |
1820 | if (rc->rc_tried) | |
1821 | continue; | |
1822 | zio_nowait(zio_vdev_child_io(zio, NULL, | |
1823 | vd->vdev_child[rc->rc_devidx], | |
1824 | rc->rc_offset, rc->rc_data, rc->rc_size, | |
b128c09f | 1825 | zio->io_type, zio->io_priority, 0, |
34dc7c2f BB |
1826 | vdev_raidz_child_done, rc)); |
1827 | } while (++c < rm->rm_cols); | |
34dc7c2f | 1828 | |
b128c09f | 1829 | return; |
34dc7c2f BB |
1830 | } |
1831 | ||
1832 | /* | |
1833 | * At this point we've attempted to reconstruct the data given the | |
1834 | * errors we detected, and we've attempted to read all columns. There | |
1835 | * must, therefore, be one or more additional problems -- silent errors | |
1836 | * resulting in invalid data rather than explicit I/O errors resulting | |
45d1cae3 BB |
1837 | * in absent data. We check if there is enough additional data to |
1838 | * possibly reconstruct the data and then perform combinatorial | |
1839 | * reconstruction over all possible combinations. If that fails, | |
1840 | * we're cooked. | |
34dc7c2f | 1841 | */ |
b128c09f BB |
1842 | if (total_errors >= rm->rm_firstdatacol) { |
1843 | zio->io_error = vdev_raidz_worst_error(rm); | |
1844 | /* | |
1845 | * If there were exactly as many device errors as parity | |
1846 | * columns, yet we couldn't reconstruct the data, then at | |
1847 | * least one device must have returned bad data silently. | |
1848 | */ | |
1849 | if (total_errors == rm->rm_firstdatacol) | |
1850 | zio->io_error = zio_worst_error(zio->io_error, ECKSUM); | |
34dc7c2f | 1851 | |
45d1cae3 BB |
1852 | } else if ((code = vdev_raidz_combrec(zio, total_errors, |
1853 | data_errors)) != 0) { | |
34dc7c2f | 1854 | /* |
45d1cae3 BB |
1855 | * If we didn't use all the available parity for the |
1856 | * combinatorial reconstruction, verify that the remaining | |
1857 | * parity is correct. | |
34dc7c2f | 1858 | */ |
45d1cae3 BB |
1859 | if (code != (1 << rm->rm_firstdatacol) - 1) |
1860 | (void) raidz_parity_verify(zio, rm); | |
1861 | } else { | |
34dc7c2f | 1862 | /* |
45d1cae3 BB |
1863 | * All combinations failed to checksum. Generate checksum |
1864 | * ereports for all children. | |
34dc7c2f | 1865 | */ |
45d1cae3 | 1866 | zio->io_error = ECKSUM; |
34dc7c2f | 1867 | |
45d1cae3 BB |
1868 | if (!(zio->io_flags & ZIO_FLAG_SPECULATIVE)) { |
1869 | for (c = 0; c < rm->rm_cols; c++) { | |
1870 | rc = &rm->rm_col[c]; | |
1871 | zfs_ereport_post(FM_EREPORT_ZFS_CHECKSUM, | |
1872 | zio->io_spa, vd->vdev_child[rc->rc_devidx], | |
1873 | zio, rc->rc_offset, rc->rc_size); | |
34dc7c2f | 1874 | } |
34dc7c2f BB |
1875 | } |
1876 | } | |
1877 | ||
1878 | done: | |
1879 | zio_checksum_verified(zio); | |
1880 | ||
fb5f0bc8 | 1881 | if (zio->io_error == 0 && spa_writeable(zio->io_spa) && |
34dc7c2f | 1882 | (unexpected_errors || (zio->io_flags & ZIO_FLAG_RESILVER))) { |
34dc7c2f BB |
1883 | /* |
1884 | * Use the good data we have in hand to repair damaged children. | |
34dc7c2f | 1885 | */ |
34dc7c2f BB |
1886 | for (c = 0; c < rm->rm_cols; c++) { |
1887 | rc = &rm->rm_col[c]; | |
1888 | cvd = vd->vdev_child[rc->rc_devidx]; | |
1889 | ||
1890 | if (rc->rc_error == 0) | |
1891 | continue; | |
1892 | ||
b128c09f | 1893 | zio_nowait(zio_vdev_child_io(zio, NULL, cvd, |
34dc7c2f BB |
1894 | rc->rc_offset, rc->rc_data, rc->rc_size, |
1895 | ZIO_TYPE_WRITE, zio->io_priority, | |
fb5f0bc8 BB |
1896 | ZIO_FLAG_IO_REPAIR | (unexpected_errors ? |
1897 | ZIO_FLAG_SELF_HEAL : 0), NULL, NULL)); | |
34dc7c2f | 1898 | } |
34dc7c2f | 1899 | } |
34dc7c2f BB |
1900 | } |
1901 | ||
1902 | static void | |
1903 | vdev_raidz_state_change(vdev_t *vd, int faulted, int degraded) | |
1904 | { | |
1905 | if (faulted > vd->vdev_nparity) | |
1906 | vdev_set_state(vd, B_FALSE, VDEV_STATE_CANT_OPEN, | |
1907 | VDEV_AUX_NO_REPLICAS); | |
1908 | else if (degraded + faulted != 0) | |
1909 | vdev_set_state(vd, B_FALSE, VDEV_STATE_DEGRADED, VDEV_AUX_NONE); | |
1910 | else | |
1911 | vdev_set_state(vd, B_FALSE, VDEV_STATE_HEALTHY, VDEV_AUX_NONE); | |
1912 | } | |
1913 | ||
1914 | vdev_ops_t vdev_raidz_ops = { | |
1915 | vdev_raidz_open, | |
1916 | vdev_raidz_close, | |
34dc7c2f BB |
1917 | vdev_raidz_asize, |
1918 | vdev_raidz_io_start, | |
1919 | vdev_raidz_io_done, | |
1920 | vdev_raidz_state_change, | |
1921 | VDEV_TYPE_RAIDZ, /* name of this vdev type */ | |
1922 | B_FALSE /* not a leaf vdev */ | |
1923 | }; |