Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[karo-tx-linux.git] / block / blk-merge.c

diff --git a/block/blk-merge.c b/block/blk-merge.c
index d3b84bbb776a5fd0b3ba3238c7de20e7df93eaeb..7506c4fe0264bd6038d24108f5438fea42478508 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -220,7 +220,10 @@ new_segment:
                bvprv = bvec;
        } /* segments in rq */
 
-       if (q->dma_drain_size) {
+       if (q->dma_drain_size && q->dma_drain_needed(rq)) {
+               if (rq->cmd_flags & REQ_RW)
+                       memset(q->dma_drain_buffer, 0, q->dma_drain_size);
+
                sg->page_link &= ~0x02;
                sg = sg_next(sg);
                sg_set_page(sg, virt_to_page(q->dma_drain_buffer),
@@ -228,6 +231,7 @@ new_segment:
                            ((unsigned long)q->dma_drain_buffer) &
                            (PAGE_SIZE - 1));
                nsegs++;
+               rq->data_len += q->dma_drain_size;
        }
 
        if (sg)