]> git.ipfire.org Git - thirdparty/mdadm.git/commitdiff
raid6check: various cleanup/fixes
authorNeilBrown <neilb@suse.de>
Mon, 20 Jul 2015 04:11:33 +0000 (14:11 +1000)
committerNeilBrown <neilb@suse.de>
Mon, 20 Jul 2015 04:11:33 +0000 (14:11 +1000)
- document meaning of various arrays. In particular:
   stripes[]
   blocks[]
   blocks_page[]
   block_index_for_slot[]

  It needs to be clear if these are indexed by raid_disk
  number or syndrome number.

- changed meaning of block_index_for_slot[].  It didn't seem
  to be used consistently.  It also made use of the block numbers
  in array data ordering, which is not directly relevant for syndrome
  calculations.

- reduced number of args to autorepair and manual_repair
  There don't need both stripes[] and blocks[].  And they don't need
  diskP or diskQ.
  blocks[-1] is the P chunk, blocks[-2] is the Q chunk.
  block_index_for_slot[] can be used to find the target device for
  a particular syndrome block.

- remove stripe locking from within manual_repair, and instead
  use the global stripe locking used for check and autorepair.

- this necessitated changes to raid6_datap_recov and raid5_2data_reov
  so the P and Q blocks could be before or after the data blocks.

Signed-off-by: NeilBrown <neilb@suse.de>
raid6check.c
restripe.c

index 6909b509b1e2e26179ecb0799e673d88b791e67b..f01944053cda6505a9c091b3a5f6609fbbb50ffe 100644 (file)
@@ -44,9 +44,10 @@ 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);
+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);
+                      uint8_t **ptrs, int neg_offset);
 void xor_blocks(char *target, char **sources, int disks, int size);
 
 /* Collect per stripe consistency information */
@@ -160,38 +161,39 @@ int unlock_all_stripes(struct mdinfo *info, sighandler_t *sig) {
 }
 
 /* Autorepair */
-int autorepair(int *disk, int diskP, int diskQ, unsigned long long start, int chunk_size,
-               char *name[], int raid_disks, int data_disks, char **blocks_page,
-               char **blocks, uint8_t *p, char **stripes, int *block_index_for_slot,
+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] >= 0) {
-                       printf("Auto-repairing slot %d (%s)\n", disk[j], name[disk[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 = 0; i < raid_disks; i++) {
+                       for(i = -2; i < syndrome_disks; i++) {
                                blocks_page[i] = blocks[i] + j * CHECK_PAGE_SIZE;
                        }
-                       if (disk[j] == diskQ) {
-                               qsyndrome(p, (uint8_t*)stripes[diskQ] + j * CHECK_PAGE_SIZE, (uint8_t**)blocks_page, data_disks, 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[data_disks];
-                               int failed_block_index = block_index_for_slot[disk[j]];
-                               for(i = 0; i < data_disks; i++) {
-                                       if (failed_block_index == i) {
-                                               all_but_failed_blocks[i] = stripes[diskP] + j * 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(stripes[disk[j]] + j * CHECK_PAGE_SIZE,
-                               all_but_failed_blocks, data_disks, CHECK_PAGE_SIZE);
+                               xor_blocks(blocks_page[disk[j]],
+                                          all_but_failed_blocks, syndrome_disks,
+                                          CHECK_PAGE_SIZE);
                        }
                }
                else {
@@ -203,8 +205,11 @@ int autorepair(int *disk, int diskP, int diskQ, unsigned long long start, int ch
                int write_res = 0;
                for(j = 0; j < (chunk_size >> CHECK_PAGE_BITS); j++) {
                        if(page_to_write[j] == 1) {
-                               lseek64(source[disk[j]], offsets[disk[j]] + start * chunk_size + j * CHECK_PAGE_SIZE, SEEK_SET);
-                               write_res += write(source[disk[j]], stripes[disk[j]] + j * CHECK_PAGE_SIZE, CHECK_PAGE_SIZE);
+                               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);
                        }
                }
 
@@ -218,101 +223,83 @@ int autorepair(int *disk, int diskP, int diskQ, unsigned long long start, int ch
 }
 
 /* Manual repair */
-int manual_repair(int diskP, int diskQ, int chunk_size, int raid_disks, int data_disks,
-                 int failed_disk1, int failed_disk2, unsigned long long start, int *block_index_for_slot,
-                 char *name[], char **stripes, char **blocks, uint8_t *p, struct mdinfo *info, sighandler_t *sig,
+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 err = 0;
        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",
-              failed_disk1, name[failed_disk1],
-              failed_disk2, name[failed_disk2]);
+              fd1, name[fd1],
+              fd2, name[fd2]);
 
-       if (failed_disk1 == diskQ || failed_disk2 == diskQ) {
-               char *all_but_failed_blocks[data_disks];
+       if (failed_slot1 == -2 || failed_slot2 == -2) {
+               char *all_but_failed_blocks[syndrome_disks];
                int failed_data_or_p;
-               int failed_block_index;
 
-               if (failed_disk1 == diskQ) {
-                       failed_data_or_p = failed_disk2;
-               }
-               else {
-                       failed_data_or_p = failed_disk1;
-               }
+               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);
-               failed_block_index = block_index_for_slot[failed_data_or_p];
-               for (i = 0; i < data_disks; i++) {
-                       if (failed_block_index == i) {
-                               all_but_failed_blocks[i] = stripes[diskP];
-                       }
-                       else {
+
+               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(stripes[failed_data_or_p],
-                          all_but_failed_blocks, data_disks, chunk_size);
-               qsyndrome(p, (uint8_t*)stripes[diskQ], (uint8_t**)blocks, data_disks, chunk_size);
-       }
-       else {
+               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_disk1 == diskP || failed_disk2 == diskP) {
-                       int failed_data, failed_block_index;
-                       if (failed_disk1 == diskP) {
-                               failed_data = failed_disk2;
-                       }
-                       else {
-                               failed_data = failed_disk1;
-                       }
-                       failed_block_index = block_index_for_slot[failed_data];
-                       printf("Repairing D(%d) and P\n", failed_data);
-                       raid6_datap_recov(raid_disks, chunk_size, failed_block_index, (uint8_t**)blocks);
-               }
-               else {
+               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");
-                       int failed_block_index1 = block_index_for_slot[failed_disk1];
-                       int failed_block_index2 = block_index_for_slot[failed_disk2];
-                       if (failed_block_index1 > failed_block_index2) {
-                               int t = failed_block_index1;
-                               failed_block_index1 = failed_block_index2;
-                               failed_block_index2 = t;
+                       if (failed_slot1 > failed_slot2) {
+                               int t = failed_slot1;
+                               failed_slot1 = failed_slot2;
+                               failed_slot2 = t;
                        }
-                       raid6_2data_recov(raid_disks, chunk_size, failed_block_index1, failed_block_index2, (uint8_t**)blocks);
+                       raid6_2data_recov(syndrome_disks+2, chunk_size,
+                                         failed_slot1, failed_slot2,
+                                         (uint8_t**)blocks, 1);
                }
        }
 
-       err = lock_stripe(info, start, chunk_size, data_disks, sig);
-       if(err != 0) {
-               if (err != 2) {
-                       return -1;
-               }
-               return -2;;
-       }
-
        int write_res1, write_res2;
        off64_t seek_res;
 
-       seek_res = lseek64(source[failed_disk1],
-                          offsets[failed_disk1] + start * chunk_size, SEEK_SET);
+       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[failed_disk1], stripes[failed_disk1], chunk_size);
+       write_res1 = write(source[fd1], blocks[failed_slot1], chunk_size);
 
-       seek_res = lseek64(source[failed_disk2],
-                          offsets[failed_disk2] + start * chunk_size, SEEK_SET);
+       seek_res = lseek64(source[fd2],
+                          offsets[fd2] + start * chunk_size, SEEK_SET);
        if (seek_res < 0) {
-               fprintf(stderr, "lseek failed for failed_disk1\n");
+               fprintf(stderr, "lseek failed for failed_disk2\n");
                return -1;
        }
-       write_res2 = write(source[failed_disk2], stripes[failed_disk2], chunk_size);
-
-       err = unlock_all_stripes(info, sig);
-       if(err != 0) {
-               return -2;
-       }
+       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");
@@ -331,10 +318,27 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
        int data_disks = raid_disks - 2;
        int syndrome_disks = data_disks + is_ddf(layout) * 2;
        char *stripe_buf = xmalloc(raid_disks * chunk_size);
+
+       /* 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*));
-       char **blocks_page = xmalloc(raid_disks * 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);
@@ -350,11 +354,19 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
        if (!tables_ready)
                make_tables();
 
+       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);
@@ -382,7 +394,13 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
                }
 
                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 */
@@ -396,46 +414,47 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
                                if (diskD >= raid_disks)
                                        diskD = 0;
                                blocks[i] = stripes[diskD];
-                               block_index_for_slot[diskD] = i;
+                               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)
+                       for (i = 0 ; i < raid_disks; i++) {
+                               if (i == diskP || i == diskQ) {
                                        blocks[i] = zero;
-                               else
+                                       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);
-               blocks[syndrome_disks] = stripes[diskP];
-               block_index_for_slot[diskP] = data_disks;
-               blocks[syndrome_disks+1] = stripes[diskQ];
-               block_index_for_slot[diskQ] = data_disks+1;
 
                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(disk[j] >= -2) {
-                               disk[j] = geo_map(disk[j], start, raid_disks, level, layout);
-                       }
-                       if(disk[j] >= 0) {
-                               printf("Error detected at stripe %llu, page %d: possible failed disk slot %d: %d --> %s\n",
-                                      start, j, role, disk[j], name[disk[j]]);
-                       }
-                       if(disk[j] == -65535) {
+                       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, diskP, diskQ, start, chunk_size,
-                                       name, raid_disks, data_disks, blocks_page,
-                                       blocks, p, stripes, block_index_for_slot,
+                       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);
@@ -443,22 +462,30 @@ int check_stripes(struct mdinfo *info, int *source, unsigned long long *offsets,
                        }
                }
 
-               err = unlock_all_stripes(info, sig);
-               if(err != 0) {
-                       goto exitCheck;
-               }
-
                if(repair == MANUAL_REPAIR) {
-                       err = manual_repair(diskP, diskQ, chunk_size, raid_disks, data_disks,
-                                       failed_disk1, failed_disk2, start, block_index_for_slot,
-                                       name, stripes, blocks, p, info, sig,
-                                       source, offsets);
+                       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++;
        }
@@ -467,9 +494,9 @@ exitCheck:
 
        free(stripe_buf);
        free(stripes);
-       free(blocks);
-       free(blocks_page);
-       free(block_index_for_slot);
+       free(blocks-2);
+       free(blocks_page-2);
+       free(block_index_for_slot-2);
        free(p);
        free(q);
        free(results);
index 40d606154ac3a18e23fad4bcdb391a3cdede96b4..1c859a3058a417467f18aa2597e5d0d6b984df95 100644 (file)
@@ -345,16 +345,22 @@ void ensure_zero_has_size(int 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 **ptrs, int neg_offset)
 {
        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];
+       if (neg_offset) {
+               p = ptrs[-1];
+               q = ptrs[-2];
+       } else {
+               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
@@ -385,13 +391,19 @@ void raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
 }
 
 /* Recover failure of one data block plus the P block */
-void raid6_datap_recov(int disks, size_t bytes, int faila, uint8_t **ptrs)
+void raid6_datap_recov(int disks, size_t bytes, int faila, uint8_t **ptrs,
+                      int neg_offset)
 {
        uint8_t *p, *q, *dq;
        const uint8_t *qmul;            /* Q multiplier table */
 
-       p = ptrs[disks-2];
-       q = ptrs[disks-1];
+       if (neg_offset) {
+               p = ptrs[-1];
+               q = ptrs[-2];
+       } else {
+               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 */
@@ -637,7 +649,7 @@ int save_stripes(int *source, unsigned long long *offsets,
                        if (fblock[1] == data_disks)
                                /* One data failed, and parity failed */
                                raid6_datap_recov(syndrome_disks+2, chunk_size,
-                                                 fdisk[0], bufs);
+                                                 fdisk[0], bufs, 0);
                        else {
                                if (fdisk[0] > fdisk[1]) {
                                        int t = fdisk[0];
@@ -646,7 +658,7 @@ int save_stripes(int *source, unsigned long long *offsets,
                                }
                                /* Two data blocks failed, P,Q OK */
                                raid6_2data_recov(syndrome_disks+2, chunk_size,
-                                                 fdisk[0], fdisk[1], bufs);
+                                                 fdisk[0], fdisk[1], bufs, 0);
                        }
                }
                if (dest) {