diff options
| -rw-r--r-- | drivers/md/raid5.c | 151 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 61 |
2 files changed, 193 insertions, 19 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 2e2e64f6ef71..c1d94ed9718b 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -1098,7 +1098,7 @@ static void shrink_stripes(raid5_conf_t *conf) static void raid5_end_read_request(struct bio * bi, int error) { - struct stripe_head *sh = bi->bi_private; + struct stripe_head *sh = bi->bi_private; raid5_conf_t *conf = sh->raid_conf; int disks = sh->disks, i; int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); @@ -1180,7 +1180,7 @@ static void raid5_end_read_request(struct bio * bi, int error) static void raid5_end_write_request(struct bio *bi, int error) { - struct stripe_head *sh = bi->bi_private; + struct stripe_head *sh = bi->bi_private; raid5_conf_t *conf = sh->raid_conf; int disks = sh->disks, i; int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); @@ -1320,20 +1320,27 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, pd_idx = stripe % raid_disks; *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; break; + case ALGORITHM_PARITY_0: + pd_idx = 0; + (*dd_idx)++; + break; + case ALGORITHM_PARITY_N: + pd_idx = data_disks; + break; default: printk(KERN_ERR "raid5: unsupported algorithm %d\n", conf->algorithm); + BUG(); } break; case 6: - /**** FIX THIS ****/ switch (conf->algorithm) { case ALGORITHM_LEFT_ASYMMETRIC: pd_idx = raid_disks - 1 - (stripe % raid_disks); qd_idx = pd_idx + 1; if (pd_idx == raid_disks-1) { - (*dd_idx)++; /* Q D D D P */ + (*dd_idx)++; /* Q D D D P */ qd_idx = 0; } else if (*dd_idx >= pd_idx) (*dd_idx) += 2; /* D D P Q D */ @@ -1342,7 +1349,7 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, pd_idx = stripe % raid_disks; qd_idx = pd_idx + 1; if (pd_idx == raid_disks-1) { - (*dd_idx)++; /* Q D D D P */ + (*dd_idx)++; /* Q D D D P */ qd_idx = 0; } else if (*dd_idx >= pd_idx) (*dd_idx) += 2; /* D D P Q D */ @@ -1357,9 +1364,89 @@ static sector_t raid5_compute_sector(raid5_conf_t *conf, sector_t r_sector, qd_idx = (pd_idx + 1) % raid_disks; *dd_idx = (pd_idx + 2 + *dd_idx) % raid_disks; break; + + case ALGORITHM_PARITY_0: + pd_idx = 0; + qd_idx = 1; + (*dd_idx) += 2; + break; + case ALGORITHM_PARITY_N: + pd_idx = data_disks; + qd_idx = data_disks + 1; + break; + + case ALGORITHM_ROTATING_ZERO_RESTART: + /* Exactly the same as RIGHT_ASYMMETRIC, but or + * of blocks for computing Q is different. + */ + pd_idx = stripe % raid_disks; + qd_idx = pd_idx + 1; + if (pd_idx == raid_disks-1) { + (*dd_idx)++; /* Q D D D P */ + qd_idx = 0; + } else if (*dd_idx >= pd_idx) + (*dd_idx) += 2; /* D D P Q D */ + break; + + case 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_idx = raid_disks - 1 - ((stripe + 1) % raid_disks); + qd_idx = pd_idx + 1; + if (pd_idx == raid_disks-1) { + (*dd_idx)++; /* Q D D D P */ + qd_idx = 0; + } else if (*dd_idx >= pd_idx) + (*dd_idx) += 2; /* D D P Q D */ + break; + + case ALGORITHM_ROTATING_N_CONTINUE: + /* Same as left_symmetric but Q is before P */ + pd_idx = raid_disks - 1 - (stripe % raid_disks); + qd_idx = (pd_idx + raid_disks - 1) % raid_disks; + *dd_idx = (pd_idx + 1 + *dd_idx) % raid_disks; + break; + + case ALGORITHM_LEFT_ASYMMETRIC_6: + /* RAID5 left_asymmetric, with Q on last device */ + pd_idx = data_disks - stripe % (raid_disks-1); + if (*dd_idx >= pd_idx) + (*dd_idx)++; + qd_idx = raid_disks - 1; + break; + + case ALGORITHM_RIGHT_ASYMMETRIC_6: + pd_idx = stripe % (raid_disks-1); + if (*dd_idx >= pd_idx) + (*dd_idx)++; + qd_idx = raid_disks - 1; + break; + + case ALGORITHM_LEFT_SYMMETRIC_6: + pd_idx = data_disks - stripe % (raid_disks-1); + *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); + qd_idx = raid_disks - 1; + break; + + case ALGORITHM_RIGHT_SYMMETRIC_6: + pd_idx = stripe % (raid_disks-1); + *dd_idx = (pd_idx + 1 + *dd_idx) % (raid_disks-1); + qd_idx = raid_disks - 1; + break; + + case ALGORITHM_PARITY_0_6: + pd_idx = 0; + (*dd_idx)++; + qd_idx = raid_disks - 1; + break; + + default: printk(KERN_CRIT "raid6: unsupported algorithm %d\n", conf->algorithm); + BUG(); } break; } @@ -1411,9 +1498,15 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) i += raid_disks; i -= (sh->pd_idx + 1); break; + case ALGORITHM_PARITY_0: + i -= 1; + break; + case ALGORITHM_PARITY_N: + break; default: printk(KERN_ERR "raid5: unsupported algorithm %d\n", conf->algorithm); + BUG(); } break; case 6: @@ -1422,8 +1515,10 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) switch (conf->algorithm) { case ALGORITHM_LEFT_ASYMMETRIC: case ALGORITHM_RIGHT_ASYMMETRIC: - if (sh->pd_idx == raid_disks-1) - i--; /* Q D D D P */ + case ALGORITHM_ROTATING_ZERO_RESTART: + case ALGORITHM_ROTATING_N_RESTART: + if (sh->pd_idx == raid_disks-1) + i--; /* Q D D D P */ else if (i > sh->pd_idx) i -= 2; /* D D P Q D */ break; @@ -1438,9 +1533,35 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i) i -= (sh->pd_idx + 2); } break; + case ALGORITHM_PARITY_0: + i -= 2; + break; + case ALGORITHM_PARITY_N: + break; + case ALGORITHM_ROTATING_N_CONTINUE: + if (sh->pd_idx == 0) + i--; /* P D D D Q */ + else if (i > sh->pd_idx) + i -= 2; /* D D Q P D */ + break; + case ALGORITHM_LEFT_ASYMMETRIC_6: + case ALGORITHM_RIGHT_ASYMMETRIC_6: + if (i > sh->pd_idx) + i--; + break; + case ALGORITHM_LEFT_SYMMETRIC_6: + case ALGORITHM_RIGHT_SYMMETRIC_6: + if (i < sh->pd_idx) + i += data_disks + 1; + i -= (sh->pd_idx + 1); + break; + case ALGORITHM_PARITY_0_6: + i -= 1; + break; default: printk(KERN_CRIT "raid6: unsupported algorithm %d\n", conf->algorithm); + BUG(); } break; } @@ -3308,7 +3429,7 @@ static int chunk_aligned_read(struct request_queue *q, struct bio * raid_bio) return 0; } /* - * use bio_clone to make a copy of the bio + * use bio_clone to make a copy of the bio */ align_bi = bio_clone(raid_bio, GFP_NOIO); if (!align_bi) @@ -3439,7 +3560,7 @@ static int make_request(struct request_queue *q, struct bio * bi) if (rw == READ && mddev->reshape_position == MaxSector && chunk_aligned_read(q,bi)) - return 0; + return 0; logical_sector = bi->bi_sector & ~((sector_t)STRIPE_SECTORS-1); last_sector = bi->bi_sector + (bi->bi_size>>9); @@ -4034,6 +4155,12 @@ static int run(mddev_t *mddev) mdname(mddev), mddev->level); return -EIO; } + if ((mddev->level == 5 && !algorithm_valid_raid5(mddev->layout)) || + (mddev->level == 6 && !algorithm_valid_raid6(mddev->layout))) { + printk(KERN_ERR "raid5: %s: layout %d not supported\n", + mdname(mddev), mddev->layout); + return -EIO; + } if (mddev->chunk_size < PAGE_SIZE) { printk(KERN_ERR "md/raid5: chunk_size must be at least " @@ -4185,12 +4312,6 @@ static int run(mddev_t *mddev) conf->chunk_size, mdname(mddev)); goto abort; } - if (conf->algorithm > ALGORITHM_RIGHT_SYMMETRIC) { - printk(KERN_ERR - "raid5: unsupported parity algorithm %d for %s\n", - conf->algorithm, mdname(mddev)); - goto abort; - } if (mddev->degraded > conf->max_degraded) { printk(KERN_ERR "raid5: not enough operational devices for %s" " (%d/%d failed)\n", diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index 0c7375ad12bd..633d79289616 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -394,9 +394,62 @@ typedef struct raid5_private_data raid5_conf_t; /* * Our supported algorithms */ -#define ALGORITHM_LEFT_ASYMMETRIC 0 -#define ALGORITHM_RIGHT_ASYMMETRIC 1 -#define ALGORITHM_LEFT_SYMMETRIC 2 -#define ALGORITHM_RIGHT_SYMMETRIC 3 +#define ALGORITHM_LEFT_ASYMMETRIC 0 /* Rotating Parity N with Data Restart */ +#define ALGORITHM_RIGHT_ASYMMETRIC 1 /* Rotating Parity 0 with Data Restart */ +#define ALGORITHM_LEFT_SYMMETRIC 2 /* Rotating Parity N with Data Continuation */ +#define ALGORITHM_RIGHT_SYMMETRIC 3 /* Rotating Parity 0 with Data Continuation */ +/* Define non-rotating (raid4) algorithms. These allow + * conversion of raid4 to raid5. + */ +#define ALGORITHM_PARITY_0 4 /* P or P,Q are initial devices */ +#define ALGORITHM_PARITY_N 5 /* P or P,Q are final devices. */ + +/* DDF RAID6 layouts differ from md/raid6 layouts in two ways. + * Firstly, the exact positioning of the parity block is slightly + * different between the 'LEFT_*' modes of md and the "_N_*" modes + * of DDF. + * Secondly, or order of datablocks over which the Q syndrome is computed + * is different. + * Consequently we have different layouts for DDF/raid6 than md/raid6. + * These layouts are from the DDFv1.2 spec. + * Interestingly DDFv1.2-Errata-A does not specify N_CONTINUE but + * leaves RLQ=3 as 'Vendor Specific' + */ + +#define ALGORITHM_ROTATING_ZERO_RESTART 8 /* DDF PRL=6 RLQ=1 */ +#define ALGORITHM_ROTATING_N_RESTART 9 /* DDF PRL=6 RLQ=2 */ +#define ALGORITHM_ROTATING_N_CONTINUE 10 /*DDF PRL=6 RLQ=3 */ + + +/* For every RAID5 algorithm we define a RAID6 algorithm + * with exactly the same layout for data and parity, and + * with the Q block always on the last device (N-1). + * This allows trivial conversion from RAID5 to RAID6 + */ +#define ALGORITHM_LEFT_ASYMMETRIC_6 16 +#define ALGORITHM_RIGHT_ASYMMETRIC_6 17 +#define ALGORITHM_LEFT_SYMMETRIC_6 18 +#define ALGORITHM_RIGHT_SYMMETRIC_6 19 +#define ALGORITHM_PARITY_0_6 20 +#define ALGORITHM_PARITY_N_6 ALGORITHM_PARITY_N + +static inline int algorithm_valid_raid5(int layout) +{ + return (layout >= 0) && + (layout <= 5); +} +static inline int algorithm_valid_raid6(int layout) +{ + return (layout >= 0 && layout <= 5) + || + (layout == 8 || layout == 10) + || + (layout >= 16 && layout <= 20); +} + +static inline int algorithm_is_DDF(int layout) +{ + return layout >= 8 && layout <= 10; +} #endif |