raid6/async_tx: handle holes in block list in async_syndrome_val
NeilBrown [Fri, 16 Oct 2009 05:40:34 +0000 (16:40 +1100)]
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>

crypto/async_tx/async_pq.c
crypto/async_tx/async_xor.c

index 9ab1ce4..43b1436 100644 (file)
@@ -260,8 +260,10 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
                                                      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 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
                         __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))
index b459a90..79182dc 100644 (file)
@@ -44,20 +44,23 @@ do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
        void *cb_param_orig = submit->cb_param;
        enum async_tx_flags flags_orig = submit->flags;
        enum dma_ctrl_flags dma_flags;
-       int xor_src_cnt;
+       int xor_src_cnt = 0;
        dma_addr_t dma_dest;
 
        /* map the dest bidrectional in case it is re-used as a source */
        dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);
        for (i = 0; i < src_cnt; i++) {
                /* only map the dest once */
+               if (!src_list[i])
+                       continue;
                if (unlikely(src_list[i] == dest)) {
-                       dma_src[i] = dma_dest;
+                       dma_src[xor_src_cnt++] = dma_dest;
                        continue;
                }
-               dma_src[i] = dma_map_page(dma->dev, src_list[i], offset,
-                                         len, DMA_TO_DEVICE);
+               dma_src[xor_src_cnt++] = dma_map_page(dma->dev, src_list[i], offset,
+                                                     len, DMA_TO_DEVICE);
        }
+       src_cnt = xor_src_cnt;
 
        while (src_cnt) {
                submit->flags = flags_orig;
@@ -123,7 +126,7 @@ do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
            int src_cnt, size_t len, struct async_submit_ctl *submit)
 {
        int i;
-       int xor_src_cnt;
+       int xor_src_cnt = 0;
        int src_off = 0;
        void *dest_buf;
        void **srcs;
@@ -135,8 +138,9 @@ do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
 
        /* convert to buffer pointers */
        for (i = 0; i < src_cnt; i++)
-               srcs[i] = page_address(src_list[i]) + offset;
-
+               if (src_list[i])
+                       srcs[xor_src_cnt++] = page_address(src_list[i]) + offset;
+       src_cnt = xor_src_cnt;
        /* set destination address */
        dest_buf = page_address(dest) + offset;