diff options
Diffstat (limited to 'raid6check.c')
| -rw-r--r-- | raid6check.c | 714 |
1 files changed, 714 insertions, 0 deletions
diff --git a/raid6check.c b/raid6check.c new file mode 100644 index 0000000..a8e6005 --- /dev/null +++ b/raid6check.c @@ -0,0 +1,714 @@ +/* + * raid6check - extended consistency check for RAID-6 + * + * Copyright (C) 2011 Piergiorgio Sartor + * + * + * 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: Piergiorgio Sartor + * Based on "restripe.c" from "mdadm" codebase + */ + +#include "mdadm.h" +#include <stdint.h> +#include <signal.h> +#include <sys/mman.h> + +#define CHECK_PAGE_BITS (12) +#define CHECK_PAGE_SIZE (1 << CHECK_PAGE_BITS) + +char const Name[] = "raid6check"; + +enum repair { + NO_REPAIR = 0, + MANUAL_REPAIR, + AUTO_REPAIR +}; + +int geo_map(int block, unsigned long long stripe, int raid_disks, + int level, int layout); +int is_ddf(int layout); +void qsyndrome(uint8_t *p, uint8_t *q, uint8_t **sources, int disks, int size); +void make_tables(void); +void ensure_zero_has_size(int chunk_size); +void raid6_datap_recov(int disks, size_t bytes, int faila, uint8_t **ptrs, + int neg_offset); +void raid6_2data_recov(int disks, size_t bytes, int faila, int failb, + uint8_t **ptrs, int neg_offset); +void xor_blocks(char *target, char **sources, int disks, int size); + +/* Collect per stripe consistency information */ +void raid6_collect(int chunk_size, uint8_t *p, uint8_t *q, + char *chunkP, char *chunkQ, int *results) +{ + int i; + int data_id; + uint8_t Px, Qx; + extern uint8_t raid6_gflog[]; + + for(i = 0; i < chunk_size; i++) { + Px = (uint8_t)chunkP[i] ^ (uint8_t)p[i]; + Qx = (uint8_t)chunkQ[i] ^ (uint8_t)q[i]; + + if((Px != 0) && (Qx == 0)) + results[i] = -1; + + if((Px == 0) && (Qx != 0)) + results[i] = -2; + + if((Px != 0) && (Qx != 0)) { + data_id = (raid6_gflog[Qx] - raid6_gflog[Px]); + if(data_id < 0) data_id += 255; + results[i] = data_id; + } + + if((Px == 0) && (Qx == 0)) + results[i] = -255; + } +} + +/* Try to find out if a specific disk has problems in a CHECK_PAGE_SIZE page size */ +int raid6_stats_blk(int *results, int raid_disks) +{ + int i; + int curr_broken_disk = -255; + int prev_broken_disk = -255; + int broken_status = 0; + + for(i = 0; i < CHECK_PAGE_SIZE; i++) { + + if(results[i] != -255) + curr_broken_disk = results[i]; + + if(curr_broken_disk >= raid_disks) + broken_status = 2; + + switch(broken_status) { + case 0: + if(curr_broken_disk != -255) { + 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 = -65535; + break; + } + } + + return curr_broken_disk; +} + +/* Collect disks status for a strip in CHECK_PAGE_SIZE page size blocks */ +void raid6_stats(int *disk, int *results, int raid_disks, int chunk_size) +{ + int i, j; + + for(i = 0, j = 0; i < chunk_size; i += CHECK_PAGE_SIZE, j++) { + disk[j] = raid6_stats_blk(&results[i], raid_disks); + } +} + +int lock_stripe(struct mdinfo *info, unsigned long long start, + int chunk_size, int data_disks, sighandler_t *sig) { + int rv; + if(mlockall(MCL_CURRENT | MCL_FUTURE) != 0) { + return 2; + } + + sig[0] = signal(SIGTERM, SIG_IGN); + sig[1] = signal(SIGINT, SIG_IGN); + sig[2] = signal(SIGQUIT, SIG_IGN); + + rv = sysfs_set_num(info, NULL, "suspend_lo", start * chunk_size * data_disks); + rv |= sysfs_set_num(info, NULL, "suspend_hi", (start + 1) * chunk_size * data_disks); + return rv * 256; +} + +int unlock_all_stripes(struct mdinfo *info, sighandler_t *sig) { + int rv; + rv = sysfs_set_num(info, NULL, "suspend_lo", 0x7FFFFFFFFFFFFFFFULL); + rv |= sysfs_set_num(info, NULL, "suspend_hi", 0); + rv |= sysfs_set_num(info, NULL, "suspend_lo", 0); + + signal(SIGQUIT, sig[2]); + signal(SIGINT, sig[1]); + signal(SIGTERM, sig[0]); + + if(munlockall() != 0) + return 3; + return rv * 256; +} + +/* Autorepair */ +int autorepair(int *disk, unsigned long long start, int chunk_size, + char *name[], int raid_disks, int syndrome_disks, char **blocks_page, + char **blocks, uint8_t *p, int *block_index_for_slot, + int *source, unsigned long long *offsets) +{ + int i, j; + int pages_to_write_count = 0; + int page_to_write[chunk_size >> CHECK_PAGE_BITS]; + for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) { + if (disk[j] >= -2 && block_index_for_slot[disk[j]] >= 0) { + int slot = block_index_for_slot[disk[j]]; + printf("Auto-repairing slot %d (%s)\n", slot, name[slot]); + pages_to_write_count++; + page_to_write[j] = 1; + for(i = -2; i < syndrome_disks; i++) { + blocks_page[i] = blocks[i] + j * CHECK_PAGE_SIZE; + } + if (disk[j] == -2) { + qsyndrome(p, (uint8_t*)blocks_page[-2], + (uint8_t**)blocks_page, + syndrome_disks, CHECK_PAGE_SIZE); + } + else { + char *all_but_failed_blocks[syndrome_disks]; + for(i = 0; i < syndrome_disks; i++) { + if (i == disk[j]) + all_but_failed_blocks[i] = blocks_page[-1]; + else + all_but_failed_blocks[i] = blocks_page[i]; + } + xor_blocks(blocks_page[disk[j]], + all_but_failed_blocks, syndrome_disks, + CHECK_PAGE_SIZE); + } + } + else { + page_to_write[j] = 0; + } + } + + if(pages_to_write_count > 0) { + int write_res = 0; + for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) { + if(page_to_write[j] == 1) { + int slot = block_index_for_slot[disk[j]]; + lseek64(source[slot], offsets[slot] + start * chunk_size + j * CHECK_PAGE_SIZE, SEEK_SET); + write_res += write(source[slot], + blocks[disk[j]] + j * CHECK_PAGE_SIZE, + CHECK_PAGE_SIZE); + } + } + + if (write_res != (CHECK_PAGE_SIZE * pages_to_write_count)) { + fprintf(stderr, "Failed to write a full chunk.\n"); + return -1; + } + } + + return 0; +} + +/* Manual repair */ +int manual_repair(int chunk_size, int syndrome_disks, + int failed_slot1, int failed_slot2, + unsigned long long start, int *block_index_for_slot, + char *name[], char **stripes, char **blocks, uint8_t *p, + int *source, unsigned long long *offsets) +{ + int i; + int fd1 = block_index_for_slot[failed_slot1]; + int fd2 = block_index_for_slot[failed_slot2]; + printf("Repairing stripe %llu\n", start); + printf("Assuming slots %d (%s) and %d (%s) are incorrect\n", + fd1, name[fd1], + fd2, name[fd2]); + + if (failed_slot1 == -2 || failed_slot2 == -2) { + char *all_but_failed_blocks[syndrome_disks]; + int failed_data_or_p; + + if (failed_slot1 == -2) + failed_data_or_p = failed_slot2; + else + failed_data_or_p = failed_slot1; + + printf("Repairing D/P(%d) and Q\n", failed_data_or_p); + + for (i = 0; i < syndrome_disks; i++) { + if (i == failed_data_or_p) + all_but_failed_blocks[i] = blocks[-1]; + else + all_but_failed_blocks[i] = blocks[i]; + } + xor_blocks(blocks[failed_data_or_p], + all_but_failed_blocks, syndrome_disks, chunk_size); + qsyndrome(p, (uint8_t*)blocks[-2], (uint8_t**)blocks, + syndrome_disks, chunk_size); + } else { + ensure_zero_has_size(chunk_size); + if (failed_slot1 == -1 || failed_slot2 == -1) { + int failed_data; + if (failed_slot1 == -1) + failed_data = failed_slot2; + else + failed_data = failed_slot1; + + printf("Repairing D(%d) and P\n", failed_data); + raid6_datap_recov(syndrome_disks+2, chunk_size, + failed_data, (uint8_t**)blocks, 1); + } else { + printf("Repairing D and D\n"); + raid6_2data_recov(syndrome_disks+2, chunk_size, + failed_slot1, failed_slot2, + (uint8_t**)blocks, 1); + } + } + + int write_res1, write_res2; + off64_t seek_res; + + seek_res = lseek64(source[fd1], + offsets[fd1] + start * chunk_size, SEEK_SET); + if (seek_res < 0) { + fprintf(stderr, "lseek failed for failed_disk1\n"); + return -1; + } + write_res1 = write(source[fd1], blocks[failed_slot1], chunk_size); + + seek_res = lseek64(source[fd2], + offsets[fd2] + start * chunk_size, SEEK_SET); + if (seek_res < 0) { + fprintf(stderr, "lseek failed for failed_disk2\n"); + return -1; + } + write_res2 = write(source[fd2], blocks[failed_slot2], chunk_size); + + if (write_res1 != chunk_size || write_res2 != chunk_size) { + fprintf(stderr, "Failed to write a complete chunk.\n"); + return -2; + } + + return 0; +} + +int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets, + int raid_disks, int chunk_size, int level, int layout, + unsigned long long start, unsigned long long length, char *name[], + enum repair repair, int failed_disk1, int failed_disk2) +{ + /* read the data and p and q blocks, and check we got them right */ + int data_disks = raid_disks - 2; + int syndrome_disks = data_disks + is_ddf(layout) * 2; + char *stripe_buf; + + /* stripes[] is indexed by raid_disk and holds chunks from each device */ + char **stripes = xmalloc(raid_disks * sizeof(char*)); + + /* blocks[] is indexed by syndrome number and points to either one of the + * chunks from 'stripes[]', or to a chunk of zeros. -1 and -2 are + * P and Q */ + char **blocks = xmalloc((syndrome_disks + 2) * sizeof(char*)); + + /* blocks_page[] is a temporary index to just one page of the chunks + * that blocks[] points to. */ + char **blocks_page = xmalloc((syndrome_disks + 2) * sizeof(char*)); + + /* block_index_for_slot[] provides the reverse mapping from blocks to stripes. + * The index is a syndrome position, the content is a raid_disk number. + * indicies -1 and -2 work, and are P and Q disks */ + int *block_index_for_slot = xmalloc((syndrome_disks+2) * sizeof(int)); + + /* 'p' and 'q' contain calcualted P and Q, to be compared with + * blocks[-1] and blocks[-2]; + */ + uint8_t *p = xmalloc(chunk_size); + uint8_t *q = xmalloc(chunk_size); + char *zero = xmalloc(chunk_size); + int *results = xmalloc(chunk_size * sizeof(int)); + sighandler_t *sig = xmalloc(3 * sizeof(sighandler_t)); + + int i, j; + int diskP, diskQ, diskD; + int err = 0; + + extern int tables_ready; + + if (!tables_ready) + make_tables(); + + if (posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size) != 0) + exit(4); + block_index_for_slot += 2; + blocks += 2; + blocks_page += 2; + + memset(zero, 0, chunk_size); + for ( i = 0 ; i < raid_disks ; i++) + stripes[i] = stripe_buf + i * chunk_size; + + while (length > 0) { + /* The syndrome number of the broken disk is recorded + * in 'disk[]' which allows a different broken disk for + * each page. + */ + int disk[chunk_size >> CHECK_PAGE_BITS]; + + err = lock_stripe(info, start, chunk_size, data_disks, sig); + if(err != 0) { + if (err != 2) + unlock_all_stripes(info, sig); + goto exitCheck; + } + for (i = 0 ; i < raid_disks ; i++) { + off64_t seek_res = lseek64(source[i], offsets[i] + start * chunk_size, + SEEK_SET); + if (seek_res < 0) { + fprintf(stderr, "lseek to source %d failed\n", i); + unlock_all_stripes(info, sig); + err = -1; + goto exitCheck; + } + int read_res = read(source[i], stripes[i], chunk_size); + if (read_res < chunk_size) { + fprintf(stderr, "Failed to read complete chunk disk %d, aborting\n", i); + unlock_all_stripes(info, sig); + err = -1; + goto exitCheck; + } + } + + diskP = geo_map(-1, start, raid_disks, level, layout); + block_index_for_slot[-1] = diskP; + blocks[-1] = stripes[diskP]; + + diskQ = geo_map(-2, start, raid_disks, level, layout); + block_index_for_slot[-2] = diskQ; + blocks[-2] = stripes[diskQ]; + + if (!is_ddf(layout)) { + /* The syndrome-order of disks starts immediately after 'Q', + * but skips P */ + diskD = diskQ; + for (i = 0 ; i < data_disks ; i++) { + diskD = diskD + 1; + if (diskD >= raid_disks) + diskD = 0; + if (diskD == diskP) + diskD += 1; + if (diskD >= raid_disks) + diskD = 0; + blocks[i] = stripes[diskD]; + block_index_for_slot[i] = diskD; + } + } else { + /* The syndrome-order exactly follows raid-disk + * numbers, with ZERO in place of P and Q + */ + for (i = 0 ; i < raid_disks; i++) { + if (i == diskP || i == diskQ) { + blocks[i] = zero; + block_index_for_slot[i] = -1; + } else { + blocks[i] = stripes[i]; + block_index_for_slot[i] = i; + } + } + } + + qsyndrome(p, q, (uint8_t**)blocks, syndrome_disks, chunk_size); + + raid6_collect(chunk_size, p, q, stripes[diskP], stripes[diskQ], results); + raid6_stats(disk, results, raid_disks, chunk_size); + + for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) { + int role = disk[j]; + if (role >= -2) { + int slot = block_index_for_slot[role]; + if (slot >= 0) + printf("Error detected at stripe %llu, page %d: possible failed disk slot %d: %d --> %s\n", + start, j, role, slot, name[slot]); + else + printf("Error detected at stripe %llu, page %d: failed slot %d should be zeros\n", + start, j, role); + } else if(disk[j] == -65535) { + printf("Error detected at stripe %llu, page %d: disk slot unknown\n", start, j); + } + } + + if(repair == AUTO_REPAIR) { + err = autorepair(disk, start, chunk_size, + name, raid_disks, syndrome_disks, blocks_page, + blocks, p, block_index_for_slot, + source, offsets); + if(err != 0) { + unlock_all_stripes(info, sig); + goto exitCheck; + } + } + + if(repair == MANUAL_REPAIR) { + int failed_slot1 = -1, failed_slot2 = -1; + for (i = -2; i < syndrome_disks; i++) { + if (block_index_for_slot[i] == failed_disk1) + failed_slot1 = i; + if (block_index_for_slot[i] == failed_disk2) + failed_slot2 = i; + } + err = manual_repair(chunk_size, syndrome_disks, + failed_slot1, failed_slot2, + start, block_index_for_slot, + name, stripes, blocks, p, + source, offsets); + if(err == -1) { + unlock_all_stripes(info, sig); + goto exitCheck; + } + } + + err = unlock_all_stripes(info, sig); + if(err != 0) { + goto exitCheck; + } + + length--; + start++; + } + +exitCheck: + + free(stripe_buf); + free(stripes); + free(blocks-2); + free(blocks_page-2); + free(block_index_for_slot-2); + free(p); + free(q); + free(results); + free(sig); + + return err; +} + +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; +} + +int main(int argc, char *argv[]) +{ + /* md_device start length */ + int *fds = NULL; + char *buf = NULL; + char **disk_name = NULL; + unsigned long long *offsets = NULL; + int raid_disks = 0; + int active_disks; + int chunk_size = 0; + int layout = -1; + int level = 6; + enum repair repair = NO_REPAIR; + int failed_disk1 = -1; + int failed_disk2 = -1; + unsigned long long start, length; + int i; + int mdfd; + struct mdinfo *info = NULL, *comp = NULL; + char *err = NULL; + int exit_err = 0; + int close_flag = 0; + char *prg = strrchr(argv[0], '/'); + + if (prg == NULL) + prg = argv[0]; + else + prg++; + + if (argc < 4) { + fprintf(stderr, "Usage: %s md_device start_stripe length_stripes [autorepair]\n", prg); + fprintf(stderr, " or: %s md_device repair stripe failed_slot_1 failed_slot_2\n", prg); + exit_err = 1; + goto exitHere; + } + + mdfd = open(argv[1], O_RDONLY); + if(mdfd < 0) { + perror(argv[1]); + fprintf(stderr, "%s: cannot open %s\n", prg, argv[1]); + exit_err = 2; + goto exitHere; + } + + info = sysfs_read(mdfd, NULL, + GET_LEVEL| + GET_LAYOUT| + GET_DISKS| + GET_STATE | + GET_COMPONENT| + GET_CHUNK| + GET_DEVS| + GET_OFFSET| + GET_SIZE); + + if(info == NULL) { + fprintf(stderr, "%s: Error reading sysfs information of %s\n", prg, argv[1]); + exit_err = 9; + goto exitHere; + } + + if(info->array.level != level) { + fprintf(stderr, "%s: %s not a RAID-6\n", prg, argv[1]); + exit_err = 3; + goto exitHere; + } + + if(info->array.failed_disks > 0) { + fprintf(stderr, "%s: %s degraded array\n", prg, argv[1]); + exit_err = 8; + goto exitHere; + } + + printf("layout: %d\n", info->array.layout); + printf("disks: %d\n", info->array.raid_disks); + printf("component size: %llu\n", info->component_size * 512); + printf("total stripes: %llu\n", (info->component_size * 512) / info->array.chunk_size); + printf("chunk size: %d\n", info->array.chunk_size); + printf("\n"); + + comp = info->devs; + for(i = 0, active_disks = 0; active_disks < info->array.raid_disks; i++) { + printf("disk: %d - offset: %llu - size: %llu - name: %s - slot: %d\n", + i, comp->data_offset * 512, comp->component_size * 512, + map_dev(comp->disk.major, comp->disk.minor, 0), + comp->disk.raid_disk); + if(comp->disk.raid_disk >= 0) + active_disks++; + comp = comp->next; + } + printf("\n"); + + close(mdfd); + + raid_disks = info->array.raid_disks; + chunk_size = info->array.chunk_size; + layout = info->array.layout; + if (strcmp(argv[2], "repair")==0) { + if (argc < 6) { + fprintf(stderr, "For repair mode, call %s md_device repair stripe failed_slot_1 failed_slot_2\n", prg); + exit_err = 1; + goto exitHere; + } + repair = MANUAL_REPAIR; + start = getnum(argv[3], &err); + length = 1; + failed_disk1 = getnum(argv[4], &err); + failed_disk2 = getnum(argv[5], &err); + + if(failed_disk1 >= info->array.raid_disks) { + fprintf(stderr, "%s: failed_slot_1 index is higher than number of devices in raid\n", prg); + exit_err = 4; + goto exitHere; + } + if(failed_disk2 >= info->array.raid_disks) { + fprintf(stderr, "%s: failed_slot_2 index is higher than number of devices in raid\n", prg); + exit_err = 4; + goto exitHere; + } + if(failed_disk1 == failed_disk2) { + fprintf(stderr, "%s: failed_slot_1 and failed_slot_2 are the same\n", prg); + exit_err = 4; + goto exitHere; + } + } + else { + start = getnum(argv[2], &err); + length = getnum(argv[3], &err); + if (argc >= 5 && strcmp(argv[4], "autorepair")==0) + repair = AUTO_REPAIR; + } + + if (err) { + fprintf(stderr, "%s: Bad number: %s\n", prg, err); + exit_err = 4; + goto exitHere; + } + + if(start > ((info->component_size * 512) / chunk_size)) { + start = (info->component_size * 512) / chunk_size; + fprintf(stderr, "%s: start beyond disks size\n", prg); + } + + if((length == 0) || + ((length + start) > ((info->component_size * 512) / chunk_size))) { + length = (info->component_size * 512) / chunk_size - start; + } + + disk_name = xmalloc(raid_disks * sizeof(*disk_name)); + fds = xmalloc(raid_disks * sizeof(*fds)); + offsets = xcalloc(raid_disks, sizeof(*offsets)); + buf = xmalloc(raid_disks * chunk_size); + + for(i=0; i<raid_disks; i++) { + fds[i] = -1; + } + close_flag = 1; + + comp = info->devs; + for (i=0, active_disks=0; active_disks<raid_disks; i++) { + int disk_slot = comp->disk.raid_disk; + if(disk_slot >= 0) { + disk_name[disk_slot] = map_dev(comp->disk.major, comp->disk.minor, 0); + offsets[disk_slot] = comp->data_offset * 512; + fds[disk_slot] = open(disk_name[disk_slot], O_RDWR | O_DIRECT); + if (fds[disk_slot] < 0) { + perror(disk_name[disk_slot]); + fprintf(stderr,"%s: cannot open %s\n", prg, disk_name[disk_slot]); + exit_err = 6; + goto exitHere; + } + active_disks++; + } + comp = comp->next; + } + + int rv = check_stripes(info, fds, offsets, + raid_disks, chunk_size, level, layout, + start, length, disk_name, repair, failed_disk1, failed_disk2); + if (rv != 0) { + fprintf(stderr, "%s: check_stripes returned %d\n", prg, rv); + exit_err = 7; + goto exitHere; + } + +exitHere: + + if (close_flag) + for(i = 0; i < raid_disks; i++) + close(fds[i]); + + free(disk_name); + free(fds); + free(offsets); + free(buf); + + exit(exit_err); +} |