The following commit has been merged in the linux branch: commit e4424fee1815f996dccd36be44d68ca160ec3e1b Author: NeilBrown neilb@suse.de Date: Fri Oct 16 16:27:34 2009 +1100

md: fix problems with RAID6 calculations for DDF.

Signed-off-by: NeilBrown neilb@suse.de

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 25c3c29..d4ce51b 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -158,11 +158,14 @@ static int raid6_idx_to_slot(int idx, struct stripe_head *sh, { int slot;

+ if (sh->ddf_layout) + slot = (*count)++; if (idx == sh->pd_idx) return syndrome_disks; if (idx == sh->qd_idx) return syndrome_disks + 1; - slot = (*count)++; + if (!sh->ddf_layout) + slot = (*count)++; return slot; }

@@ -727,9 +730,8 @@ static int set_syndrome_sources(struct page **srcs, struct stripe_head *sh) srcs[slot] = sh->dev[i].page; i = raid6_next_disk(i, disks); } while (i != d0_idx); - BUG_ON(count != syndrome_disks);

- return count; + return syndrome_disks; }

static struct dma_async_tx_descriptor * @@ -828,7 +830,6 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) failb = slot; i = raid6_next_disk(i, disks); } while (i != d0_idx); - BUG_ON(count != syndrome_disks);

BUG_ON(faila == failb); if (failb < faila) @@ -845,7 +846,7 @@ ops_run_compute6_2(struct stripe_head *sh, struct raid5_percpu *percpu) init_async_submit(&submit, ASYNC_TX_FENCE, NULL, ops_complete_compute, sh, to_addr_conv(sh, percpu)); - return async_gen_syndrome(blocks, 0, count+2, + return async_gen_syndrome(blocks, 0, syndrome_disks+2, STRIPE_SIZE, &submit); } else { struct page *dest; @@ -1935,10 +1936,15 @@ static sector_t compute_blocknr(struct stripe_head *sh, int i, int previous) case ALGORITHM_PARITY_N: break; case ALGORITHM_ROTATING_N_CONTINUE: + /* Like left_symmetric, but P is before Q */ if (sh->pd_idx == 0) i--; /* P D D D Q */ - else if (i > sh->pd_idx) - i -= 2; /* D D Q P D */ + else { + /* D D Q P D */ + if (i < sh->pd_idx) + i += raid_disks; + i -= (sh->pd_idx + 1); + } break; case ALGORITHM_LEFT_ASYMMETRIC_6: case ALGORITHM_RIGHT_ASYMMETRIC_6: diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h index dcefdc9..dd70835 100644 --- a/drivers/md/raid5.h +++ b/drivers/md/raid5.h @@ -488,7 +488,7 @@ static inline int algorithm_valid_raid6(int layout) { return (layout >= 0 && layout <= 5) || - (layout == 8 || layout == 10) + (layout >= 8 && layout <= 10) || (layout >= 16 && layout <= 20); }