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Diffstat (limited to 'restripe.c')
| -rw-r--r-- | restripe.c | 994 |
1 files changed, 994 insertions, 0 deletions
diff --git a/restripe.c b/restripe.c new file mode 100644 index 00000000..93ef056e --- /dev/null +++ b/restripe.c @@ -0,0 +1,994 @@ +/* + * mdadm - manage Linux "md" devices aka RAID arrays. + * + * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de> + * + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Neil Brown + * Email: <neilb@suse.de> + */ + +#include "mdadm.h" +#include <stdint.h> + +/* To restripe, we read from old geometry to a buffer, and + * read from buffer to new geometry. + * When reading, we might have missing devices and so could need + * to reconstruct. + * When writing, we need to create correct parity and Q. + * + */ + +int geo_map(int block, unsigned long long stripe, int raid_disks, + int level, int layout) +{ + /* On the given stripe, find which disk in the array will have + * block numbered 'block'. + * '-1' means the parity block. + * '-2' means the Q syndrome. + */ + int pd; + + /* layout is not relevant for raid0 and raid4 */ + if ((level == 0) || + (level == 4)) + layout = 0; + + switch(level*100 + layout) { + case 000: + case 400: + case 500 + ALGORITHM_PARITY_N: + /* raid 4 isn't messed around by parity blocks */ + if (block == -1) + return raid_disks-1; /* parity block */ + return block; + case 500 + ALGORITHM_LEFT_ASYMMETRIC: + pd = (raid_disks-1) - stripe % raid_disks; + if (block == -1) return pd; + if (block >= pd) + block++; + return block; + + case 500 + ALGORITHM_RIGHT_ASYMMETRIC: + pd = stripe % raid_disks; + if (block == -1) return pd; + if (block >= pd) + block++; + return block; + + case 500 + ALGORITHM_LEFT_SYMMETRIC: + pd = (raid_disks - 1) - stripe % raid_disks; + if (block == -1) return pd; + return (pd + 1 + block) % raid_disks; + + case 500 + ALGORITHM_RIGHT_SYMMETRIC: + pd = stripe % raid_disks; + if (block == -1) return pd; + return (pd + 1 + block) % raid_disks; + + case 500 + ALGORITHM_PARITY_0: + return block + 1; + + case 600 + ALGORITHM_PARITY_N_6: + if (block == -2) + return raid_disks - 1; + if (block == -1) + return raid_disks - 2; /* parity block */ + return block; + case 600 + ALGORITHM_LEFT_ASYMMETRIC_6: + if (block == -2) + return raid_disks - 1; + raid_disks--; + pd = (raid_disks-1) - stripe % raid_disks; + if (block == -1) return pd; + if (block >= pd) + block++; + return block; + + case 600 + ALGORITHM_RIGHT_ASYMMETRIC_6: + if (block == -2) + return raid_disks - 1; + raid_disks--; + pd = stripe % raid_disks; + if (block == -1) return pd; + if (block >= pd) + block++; + return block; + + case 600 + ALGORITHM_LEFT_SYMMETRIC_6: + if (block == -2) + return raid_disks - 1; + raid_disks--; + pd = (raid_disks - 1) - stripe % raid_disks; + if (block == -1) return pd; + return (pd + 1 + block) % raid_disks; + + case 600 + ALGORITHM_RIGHT_SYMMETRIC_6: + if (block == -2) + return raid_disks - 1; + raid_disks--; + pd = stripe % raid_disks; + if (block == -1) return pd; + return (pd + 1 + block) % raid_disks; + + case 600 + ALGORITHM_PARITY_0_6: + if (block == -2) + return raid_disks - 1; + return block + 1; + + case 600 + ALGORITHM_PARITY_0: + if (block == -1) + return 0; + if (block == -2) + return 1; + return block + 2; + + case 600 + ALGORITHM_LEFT_ASYMMETRIC: + pd = raid_disks - 1 - (stripe % raid_disks); + if (block == -1) return pd; + if (block == -2) return (pd+1) % raid_disks; + if (pd == raid_disks - 1) + return block+1; + if (block >= pd) + return block+2; + return block; + + case 600 + ALGORITHM_ROTATING_ZERO_RESTART: + /* Different order for calculating Q, otherwize same as ... */ + case 600 + ALGORITHM_RIGHT_ASYMMETRIC: + pd = stripe % raid_disks; + if (block == -1) return pd; + if (block == -2) return (pd+1) % raid_disks; + if (pd == raid_disks - 1) + return block+1; + if (block >= pd) + return block+2; + return block; + + case 600 + ALGORITHM_LEFT_SYMMETRIC: + pd = raid_disks - 1 - (stripe % raid_disks); + if (block == -1) return pd; + if (block == -2) return (pd+1) % raid_disks; + return (pd + 2 + block) % raid_disks; + + case 600 + ALGORITHM_RIGHT_SYMMETRIC: + pd = stripe % raid_disks; + if (block == -1) return pd; + if (block == -2) return (pd+1) % raid_disks; + return (pd + 2 + block) % raid_disks; + + case 600 + ALGORITHM_ROTATING_N_RESTART: + /* Same a left_asymmetric, by first stripe is + * D D D P Q rather than + * Q D D D P + */ + pd = raid_disks - 1 - ((stripe + 1) % raid_disks); + if (block == -1) return pd; + if (block == -2) return (pd+1) % raid_disks; + if (pd == raid_disks - 1) + return block+1; + if (block >= pd) + return block+2; + return block; + + case 600 + ALGORITHM_ROTATING_N_CONTINUE: + /* Same as left_symmetric but Q is before P */ + pd = raid_disks - 1 - (stripe % raid_disks); + if (block == -1) return pd; + if (block == -2) return (pd+raid_disks-1) % raid_disks; + return (pd + 1 + block) % raid_disks; + } + return -1; +} +static int is_ddf(int layout) +{ + switch (layout) + { + default: + return 0; + case ALGORITHM_ROTATING_N_CONTINUE: + case ALGORITHM_ROTATING_N_RESTART: + case ALGORITHM_ROTATING_ZERO_RESTART: + return 1; + } +} + +void xor_blocks(char *target, char **sources, int disks, int size) +{ + int i, j; + /* Amazingly inefficient... */ + for (i=0; i<size; i++) { + char c = 0; + for (j=0 ; j<disks; j++) + c ^= sources[j][i]; + target[i] = c; + } +} + +void qsyndrome(uint8_t *p, uint8_t *q, uint8_t **sources, int disks, int size) +{ + int d, z; + uint8_t wq0, wp0, wd0, w10, w20; + for ( d = 0; d < size; d++) { + wq0 = wp0 = sources[disks-1][d]; + for ( z = disks-2 ; z >= 0 ; z-- ) { + wd0 = sources[z][d]; + wp0 ^= wd0; + w20 = (wq0&0x80) ? 0xff : 0x00; + w10 = (wq0 << 1) & 0xff; + w20 &= 0x1d; + w10 ^= w20; + wq0 = w10 ^ wd0; + } + p[d] = wp0; + q[d] = wq0; + } +} + +/* + * The following was taken from linux/drivers/md/mktables.c, and modified + * to create in-memory tables rather than C code + */ +static uint8_t gfmul(uint8_t a, uint8_t b) +{ + uint8_t v = 0; + + while (b) { + if (b & 1) + v ^= a; + a = (a << 1) ^ (a & 0x80 ? 0x1d : 0); + b >>= 1; + } + + return v; +} + +static uint8_t gfpow(uint8_t a, int b) +{ + uint8_t v = 1; + + b %= 255; + if (b < 0) + b += 255; + + while (b) { + if (b & 1) + v = gfmul(v, a); + a = gfmul(a, a); + b >>= 1; + } + + return v; +} + +int tables_ready = 0; +uint8_t raid6_gfmul[256][256]; +uint8_t raid6_gfexp[256]; +uint8_t raid6_gfinv[256]; +uint8_t raid6_gfexi[256]; +uint8_t raid6_gflog[256]; +uint8_t raid6_gfilog[256]; +void make_tables(void) +{ + int i, j; + uint8_t v; + uint32_t b, log; + + /* Compute multiplication table */ + for (i = 0; i < 256; i++) + for (j = 0; j < 256; j++) + raid6_gfmul[i][j] = gfmul(i, j); + + /* Compute power-of-2 table (exponent) */ + v = 1; + for (i = 0; i < 256; i++) { + raid6_gfexp[i] = v; + v = gfmul(v, 2); + if (v == 1) + v = 0; /* For entry 255, not a real entry */ + } + + /* Compute inverse table x^-1 == x^254 */ + for (i = 0; i < 256; i++) + raid6_gfinv[i] = gfpow(i, 254); + + /* Compute inv(2^x + 1) (exponent-xor-inverse) table */ + for (i = 0; i < 256; i ++) + raid6_gfexi[i] = raid6_gfinv[raid6_gfexp[i] ^ 1]; + + /* Compute log and inverse log */ + /* Modified code from: + * http://web.eecs.utk.edu/~plank/plank/papers/CS-96-332.html + */ + b = 1; + raid6_gflog[0] = 0; + raid6_gfilog[255] = 0; + + for (log = 0; log < 255; log++) { + raid6_gflog[b] = (uint8_t) log; + raid6_gfilog[log] = (uint8_t) b; + b = b << 1; + if (b & 256) b = b ^ 0435; + } + + tables_ready = 1; +} + +uint8_t *zero; +int zero_size; + +void ensure_zero_has_size(int chunk_size) +{ + if (zero == NULL || chunk_size > zero_size) { + if (zero) + free(zero); + zero = xcalloc(1, chunk_size); + zero_size = chunk_size; + } +} + +/* Following was taken from linux/drivers/md/raid6recov.c */ + +/* Recover two failed data blocks. */ +void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, + uint8_t **ptrs) +{ + uint8_t *p, *q, *dp, *dq; + uint8_t px, qx, db; + const uint8_t *pbmul; /* P multiplier table for B data */ + const uint8_t *qmul; /* Q multiplier table (for both) */ + + p = ptrs[disks-2]; + q = ptrs[disks-1]; + + /* Compute syndrome with zero for the missing data pages + Use the dead data pages as temporary storage for + delta p and delta q */ + dp = ptrs[faila]; + ptrs[faila] = zero; + dq = ptrs[failb]; + ptrs[failb] = zero; + + qsyndrome(dp, dq, ptrs, disks-2, bytes); + + /* Restore pointer table */ + ptrs[faila] = dp; + ptrs[failb] = dq; + + /* Now, pick the proper data tables */ + pbmul = raid6_gfmul[raid6_gfexi[failb-faila]]; + qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]]]; + + /* Now do it... */ + while ( bytes-- ) { + px = *p ^ *dp; + qx = qmul[*q ^ *dq]; + *dq++ = db = pbmul[px] ^ qx; /* Reconstructed B */ + *dp++ = db ^ px; /* Reconstructed A */ + p++; q++; + } +} + +/* Recover failure of one data block plus the P block */ +void raid6_datap_recov(int disks, size_t bytes, int faila, uint8_t **ptrs) +{ + uint8_t *p, *q, *dq; + const uint8_t *qmul; /* Q multiplier table */ + + p = ptrs[disks-2]; + q = ptrs[disks-1]; + + /* Compute syndrome with zero for the missing data page + Use the dead data page as temporary storage for delta q */ + dq = ptrs[faila]; + ptrs[faila] = zero; + + qsyndrome(p, dq, ptrs, disks-2, bytes); + + /* Restore pointer table */ + ptrs[faila] = dq; + + /* Now, pick the proper data tables */ + qmul = raid6_gfmul[raid6_gfinv[raid6_gfexp[faila]]]; + + /* Now do it... */ + while ( bytes-- ) { + *p++ ^= *dq = qmul[*q ^ *dq]; + q++; dq++; + } +} + +/* Try to find out if a specific disk has a problem */ +int raid6_check_disks(int data_disks, int start, int chunk_size, + int level, int layout, int diskP, int diskQ, + char *p, char *q, char **stripes) +{ + int i; + int data_id, diskD; + uint8_t Px, Qx; + int curr_broken_disk = -1; + int prev_broken_disk = -1; + int broken_status = 0; + + for(i = 0; i < chunk_size; i++) { + Px = (uint8_t)stripes[diskP][i] ^ (uint8_t)p[i]; + Qx = (uint8_t)stripes[diskQ][i] ^ (uint8_t)q[i]; + + if((Px != 0) && (Qx == 0)) + curr_broken_disk = diskP; + + if((Px == 0) && (Qx != 0)) + curr_broken_disk = diskQ; + + if((Px != 0) && (Qx != 0)) { + data_id = (raid6_gflog[Qx] - raid6_gflog[Px]); + if(data_id < 0) data_id += 255; + diskD = geo_map(data_id, start/chunk_size, + data_disks + 2, level, layout); + curr_broken_disk = diskD; + } + + if((Px == 0) && (Qx == 0)) + curr_broken_disk = curr_broken_disk; + + if(curr_broken_disk >= data_disks + 2) + broken_status = 2; + + switch(broken_status) { + case 0: + if(curr_broken_disk != -1) { + prev_broken_disk = curr_broken_disk; + broken_status = 1; + } + break; + + case 1: + if(curr_broken_disk != prev_broken_disk) + broken_status = 2; + break; + + case 2: + default: + curr_broken_disk = prev_broken_disk = -2; + break; + } + } + + return curr_broken_disk; +} + +/******************************************************************************* + * Function: save_stripes + * Description: + * Function reads data (only data without P and Q) from array and writes + * it to buf and opcjonaly to backup files + * Parameters: + * source : A list of 'fds' of the active disks. + * Some may be absent + * offsets : A list of offsets on disk belonging + * to the array [bytes] + * raid_disks : geometry: number of disks in the array + * chunk_size : geometry: chunk size [bytes] + * level : geometry: RAID level + * layout : geometry: layout + * nwrites : number of backup files + * dest : A list of 'fds' for mirrored targets + * (e.g. backup files). They are already seeked to right + * (write) location. If NULL, data will be wrote + * to the buf only + * start : start address of data to read (must be stripe-aligned) + * [bytes] + * length - : length of data to read (must be stripe-aligned) + * [bytes] + * buf : buffer for data. It is large enough to hold + * one stripe. It is stripe aligned + * Returns: + * 0 : success + * -1 : fail + ******************************************************************************/ +int save_stripes(int *source, unsigned long long *offsets, + int raid_disks, int chunk_size, int level, int layout, + int nwrites, int *dest, + unsigned long long start, unsigned long long length, + char *buf) +{ + int len; + int data_disks = raid_disks - (level == 0 ? 0 : level <=5 ? 1 : 2); + int disk; + int i; + unsigned long long length_test; + + if (!tables_ready) + make_tables(); + ensure_zero_has_size(chunk_size); + + len = data_disks * chunk_size; + length_test = length / len; + length_test *= len; + + if (length != length_test) { + dprintf("Error: save_stripes(): Data are not alligned. EXIT\n"); + dprintf("\tArea for saving stripes (length) = %llu\n", length); + dprintf("\tWork step (len) = %i\n", len); + dprintf("\tExpected save area (length_test) = %llu\n", + length_test); + abort(); + } + + while (length > 0) { + int failed = 0; + int fdisk[3], fblock[3]; + for (disk = 0; disk < raid_disks ; disk++) { + unsigned long long offset; + int dnum; + + offset = (start/chunk_size/data_disks)*chunk_size; + dnum = geo_map(disk < data_disks ? disk : data_disks - disk - 1, + start/chunk_size/data_disks, + raid_disks, level, layout); + if (dnum < 0) abort(); + if (source[dnum] < 0 || + lseek64(source[dnum], offsets[dnum]+offset, 0) < 0 || + read(source[dnum], buf+disk * chunk_size, chunk_size) + != chunk_size) + if (failed <= 2) { + fdisk[failed] = dnum; + fblock[failed] = disk; + failed++; + } + } + if (failed == 0 || fblock[0] >= data_disks) + /* all data disks are good */ + ; + else if (failed == 1 || fblock[1] >= data_disks+1) { + /* one failed data disk and good parity */ + char *bufs[data_disks]; + for (i=0; i < data_disks; i++) + if (fblock[0] == i) + bufs[i] = buf + data_disks*chunk_size; + else + bufs[i] = buf + i*chunk_size; + + xor_blocks(buf + fblock[0]*chunk_size, + bufs, data_disks, chunk_size); + } else if (failed > 2 || level != 6) + /* too much failure */ + return -1; + else { + /* RAID6 computations needed. */ + uint8_t *bufs[data_disks+4]; + int qdisk; + int syndrome_disks; + disk = geo_map(-1, start/chunk_size/data_disks, + raid_disks, level, layout); + qdisk = geo_map(-2, start/chunk_size/data_disks, + raid_disks, level, layout); + if (is_ddf(layout)) { + /* q over 'raid_disks' blocks, in device order. + * 'p' and 'q' get to be all zero + */ + for (i = 0; i < raid_disks; i++) + bufs[i] = zero; + for (i = 0; i < data_disks; i++) { + int dnum = geo_map(i, + start/chunk_size/data_disks, + raid_disks, level, layout); + int snum; + /* i is the logical block number, so is index to 'buf'. + * dnum is physical disk number + * and thus the syndrome number. + */ + snum = dnum; + bufs[snum] = (uint8_t*)buf + chunk_size * i; + } + syndrome_disks = raid_disks; + } else { + /* for md, q is over 'data_disks' blocks, + * starting immediately after 'q' + * Note that for the '_6' variety, the p block + * makes a hole that we need to be careful of. + */ + int j; + int snum = 0; + for (j = 0; j < raid_disks; j++) { + int dnum = (qdisk + 1 + j) % raid_disks; + if (dnum == disk || dnum == qdisk) + continue; + for (i = 0; i < data_disks; i++) + if (geo_map(i, + start/chunk_size/data_disks, + raid_disks, level, layout) == dnum) + break; + /* i is the logical block number, so is index to 'buf'. + * dnum is physical disk number + * snum is syndrome disk for which 0 is immediately after Q + */ + bufs[snum] = (uint8_t*)buf + chunk_size * i; + + if (fblock[0] == i) + fdisk[0] = snum; + if (fblock[1] == i) + fdisk[1] = snum; + snum++; + } + + syndrome_disks = data_disks; + } + + /* Place P and Q blocks at end of bufs */ + bufs[syndrome_disks] = (uint8_t*)buf + chunk_size * data_disks; + bufs[syndrome_disks+1] = (uint8_t*)buf + chunk_size * (data_disks+1); + + if (fblock[1] == data_disks) + /* One data failed, and parity failed */ + raid6_datap_recov(syndrome_disks+2, chunk_size, + fdisk[0], bufs); + else { + if (fdisk[0] > fdisk[1]) { + int t = fdisk[0]; + fdisk[0] = fdisk[1]; + fdisk[1] = t; + } + /* Two data blocks failed, P,Q OK */ + raid6_2data_recov(syndrome_disks+2, chunk_size, + fdisk[0], fdisk[1], bufs); + } + } + if (dest) { + for (i = 0; i < nwrites; i++) + if (write(dest[i], buf, len) != len) + return -1; + } else { + /* build next stripe in buffer */ + buf += len; + } + length -= len; + start += len; + } + return 0; +} + +/* Restore data: + * We are given: + * A list of 'fds' of the active disks. Some may be '-1' for not-available. + * A geometry: raid_disks, chunk_size, level, layout + * An 'fd' to read from. It is already seeked to the right (Read) location. + * A start and length. + * The length must be a multiple of the stripe size. + * + * We build a full stripe in memory and then write it out. + * We assume that there are enough working devices. + */ +int restore_stripes(int *dest, unsigned long long *offsets, + int raid_disks, int chunk_size, int level, int layout, + int source, unsigned long long read_offset, + unsigned long long start, unsigned long long length, + char *src_buf) +{ + char *stripe_buf; + char **stripes = xmalloc(raid_disks * sizeof(char*)); + char **blocks = xmalloc(raid_disks * sizeof(char*)); + int i; + int rv; + + int data_disks = raid_disks - (level == 0 ? 0 : level <= 5 ? 1 : 2); + + if (posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size)) + stripe_buf = NULL; + + if (zero == NULL || chunk_size > zero_size) { + if (zero) + free(zero); + zero = xcalloc(1, chunk_size); + zero_size = chunk_size; + } + + if (stripe_buf == NULL || stripes == NULL || blocks == NULL + || zero == NULL) { + rv = -2; + goto abort; + } + for (i = 0; i < raid_disks; i++) + stripes[i] = stripe_buf + i * chunk_size; + while (length > 0) { + unsigned int len = data_disks * chunk_size; + unsigned long long offset; + int disk, qdisk; + int syndrome_disks; + if (length < len) { + rv = -3; + goto abort; + } + for (i = 0; i < data_disks; i++) { + int disk = geo_map(i, start/chunk_size/data_disks, + raid_disks, level, layout); + if (src_buf == NULL) { + /* read from file */ + if (lseek64(source, read_offset, 0) != + (off64_t)read_offset) { + rv = -1; + goto abort; + } + if (read(source, + stripes[disk], + chunk_size) != chunk_size) { + rv = -1; + goto abort; + } + } else { + /* read from input buffer */ + memcpy(stripes[disk], + src_buf + read_offset, + chunk_size); + } + read_offset += chunk_size; + } + /* We have the data, now do the parity */ + offset = (start/chunk_size/data_disks) * chunk_size; + switch (level) { + case 4: + case 5: + disk = geo_map(-1, start/chunk_size/data_disks, + raid_disks, level, layout); + for (i = 0; i < data_disks; i++) + blocks[i] = stripes[(disk+1+i) % raid_disks]; + xor_blocks(stripes[disk], blocks, data_disks, chunk_size); + break; + case 6: + disk = geo_map(-1, start/chunk_size/data_disks, + raid_disks, level, layout); + qdisk = geo_map(-2, start/chunk_size/data_disks, + raid_disks, level, layout); + if (is_ddf(layout)) { + /* q over 'raid_disks' blocks, in device order. + * 'p' and 'q' get to be all zero + */ + for (i = 0; i < raid_disks; i++) + if (i == disk || i == qdisk) + blocks[i] = (char*)zero; + else + blocks[i] = stripes[i]; + syndrome_disks = raid_disks; + } else { + /* for md, q is over 'data_disks' blocks, + * starting immediately after 'q' + */ + for (i = 0; i < data_disks; i++) + blocks[i] = stripes[(qdisk+1+i) % raid_disks]; + + syndrome_disks = data_disks; + } + qsyndrome((uint8_t*)stripes[disk], + (uint8_t*)stripes[qdisk], + (uint8_t**)blocks, + syndrome_disks, chunk_size); + break; + } + for (i=0; i < raid_disks ; i++) + if (dest[i] >= 0) { + if (lseek64(dest[i], + offsets[i]+offset, 0) < 0) { + rv = -1; + goto abort; + } + if (write(dest[i], stripes[i], + chunk_size) != chunk_size) { + rv = -1; + goto abort; + } + } + length -= len; + start += len; + } + rv = 0; + +abort: + free(stripe_buf); + free(stripes); + free(blocks); + return rv; +} + +#ifdef MAIN + +int test_stripes(int *source, unsigned long long *offsets, + int raid_disks, int chunk_size, int level, int layout, + unsigned long long start, unsigned long long length) +{ + /* ready the data and p (and q) blocks, and check we got them right */ + char *stripe_buf = xmalloc(raid_disks * chunk_size); + char **stripes = xmalloc(raid_disks * sizeof(char*)); + char **blocks = xmalloc(raid_disks * sizeof(char*)); + char *p = xmalloc(chunk_size); + char *q = xmalloc(chunk_size); + + int i; + int diskP, diskQ; + int data_disks = raid_disks - (level == 5 ? 1: 2); + + if (!tables_ready) + make_tables(); + + for ( i = 0 ; i < raid_disks ; i++) + stripes[i] = stripe_buf + i * chunk_size; + + while (length > 0) { + int disk; + + for (i = 0 ; i < raid_disks ; i++) { + lseek64(source[i], offsets[i]+start, 0); + read(source[i], stripes[i], chunk_size); + } + for (i = 0 ; i < data_disks ; i++) { + int disk = geo_map(i, start/chunk_size, raid_disks, + level, layout); + blocks[i] = stripes[disk]; + printf("%d->%d\n", i, disk); + } + switch(level) { + case 6: + qsyndrome(p, q, (uint8_t**)blocks, data_disks, chunk_size); + diskP = geo_map(-1, start/chunk_size, raid_disks, + level, layout); + if (memcmp(p, stripes[diskP], chunk_size) != 0) { + printf("P(%d) wrong at %llu\n", diskP, + start / chunk_size); + } + diskQ = geo_map(-2, start/chunk_size, raid_disks, + level, layout); + if (memcmp(q, stripes[diskQ], chunk_size) != 0) { + printf("Q(%d) wrong at %llu\n", diskQ, + start / chunk_size); + } + disk = raid6_check_disks(data_disks, start, chunk_size, + level, layout, diskP, diskQ, + p, q, stripes); + if(disk >= 0) { + printf("Possible failed disk: %d\n", disk); + } + if(disk == -2) { + printf("Failure detected, but disk unknown\n"); + } + break; + } + length -= chunk_size; + start += chunk_size; + } + return 0; +} + +unsigned long long getnum(char *str, char **err) +{ + char *e; + unsigned long long rv = strtoull(str, &e, 10); + if (e==str || *e) { + *err = str; + return 0; + } + return rv; +} + +main(int argc, char *argv[]) +{ + /* save/restore file raid_disks chunk_size level layout start length devices... + */ + int save; + int *fds; + char *file; + char *buf; + int storefd; + unsigned long long *offsets; + int raid_disks, chunk_size, level, layout; + unsigned long long start, length; + int i; + + char *err = NULL; + if (argc < 10) { + fprintf(stderr, "Usage: test_stripe save/restore file raid_disks" + " chunk_size level layout start length devices...\n"); + exit(1); + } + if (strcmp(argv[1], "save")==0) + save = 1; + else if (strcmp(argv[1], "restore") == 0) + save = 0; + else if (strcmp(argv[1], "test") == 0) + save = 2; + else { + fprintf(stderr, "test_stripe: must give 'save' or 'restore'.\n"); + exit(2); + } + + file = argv[2]; + raid_disks = getnum(argv[3], &err); + chunk_size = getnum(argv[4], &err); + level = getnum(argv[5], &err); + layout = getnum(argv[6], &err); + start = getnum(argv[7], &err); + length = getnum(argv[8], &err); + if (err) { + fprintf(stderr, "test_stripe: Bad number: %s\n", err); + exit(2); + } + if (argc != raid_disks + 9) { + fprintf(stderr, "test_stripe: wrong number of devices: want %d found %d\n", + raid_disks, argc-9); + exit(2); + } + fds = xmalloc(raid_disks * sizeof(*fds)); + offsets = xcalloc(raid_disks, sizeof(*offsets)); + + storefd = open(file, O_RDWR); + if (storefd < 0) { + perror(file); + fprintf(stderr, "test_stripe: could not open %s.\n", file); + exit(3); + } + for (i=0; i<raid_disks; i++) { + char *p; + p = strchr(argv[9+i], ':'); + + if(p != NULL) { + *p++ = '\0'; + offsets[i] = atoll(p) * 512; + } + + fds[i] = open(argv[9+i], O_RDWR); + if (fds[i] < 0) { + perror(argv[9+i]); + fprintf(stderr,"test_stripe: cannot open %s.\n", argv[9+i]); + exit(3); + } + } + + buf = xmalloc(raid_disks * chunk_size); + + if (save == 1) { + int rv = save_stripes(fds, offsets, + raid_disks, chunk_size, level, layout, + 1, &storefd, + start, length, buf); + if (rv != 0) { + fprintf(stderr, + "test_stripe: save_stripes returned %d\n", rv); + exit(1); + } + } else if (save == 2) { + int rv = test_stripes(fds, offsets, + raid_disks, chunk_size, level, layout, + start, length); + if (rv != 0) { + fprintf(stderr, + "test_stripe: test_stripes returned %d\n", rv); + exit(1); + } + } else { + int rv = restore_stripes(fds, offsets, + raid_disks, chunk_size, level, layout, + storefd, 0ULL, + start, length, NULL); + if (rv != 0) { + fprintf(stderr, + "test_stripe: restore_stripes returned %d\n", + rv); + exit(1); + } + } + exit(0); +} + +#endif /* MAIN */ |