raid6/async_tx: handle holes in block list in async_syndrome_val
async_syndrome_val check the P and Q blocks used for RAID6
calculations.
With DDF raid6, some of the data blocks might be NULL, so
this needs to be handled in the same way that async_gen_syndrome
handles it.
As async_syndrome_val calls async_xor, also enhance async_xor
to detect and skip NULL blocks in the list.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
index 9ab1ce4..43b1436 100644
--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -260,8 +260,10 @@
len);
struct dma_device *device = chan ? chan->device : NULL;
struct dma_async_tx_descriptor *tx;
+ unsigned char coefs[disks-2];
enum dma_ctrl_flags dma_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
dma_addr_t *dma_src = NULL;
+ int src_cnt = 0;
BUG_ON(disks < 4);
@@ -280,20 +282,35 @@
__func__, disks, len);
if (!P(blocks, disks))
dma_flags |= DMA_PREP_PQ_DISABLE_P;
+ else
+ pq[0] = dma_map_page(dev, P(blocks,disks),
+ offset, len,
+ DMA_TO_DEVICE);
if (!Q(blocks, disks))
dma_flags |= DMA_PREP_PQ_DISABLE_Q;
+ else
+ pq[1] = dma_map_page(dev, Q(blocks,disks),
+ offset, len,
+ DMA_TO_DEVICE);
+
if (submit->flags & ASYNC_TX_FENCE)
dma_flags |= DMA_PREP_FENCE;
- for (i = 0; i < disks; i++)
- if (likely(blocks[i]))
- dma_src[i] = dma_map_page(dev, blocks[i],
- offset, len,
- DMA_TO_DEVICE);
+ for (i = 0; i < disks-2; i++)
+ if (likely(blocks[i])) {
+ dma_src[src_cnt] = dma_map_page(dev, blocks[i],
+ offset, len,
+ DMA_TO_DEVICE);
+ coefs[src_cnt] = raid6_gfexp[i];
+ src_cnt++;
+ }
+ pq[1] = dma_map_page(dev, Q(blocks,disks),
+ offset, len,
+ DMA_TO_DEVICE);
for (;;) {
tx = device->device_prep_dma_pq_val(chan, pq, dma_src,
- disks - 2,
- raid6_gfexp,
+ src_cnt,
+ coefs,
len, pqres,
dma_flags);
if (likely(tx))