NVMe: Handle physical merging of bvec entries
In order to not overrun the sg array, we have to merge physically
contiguous pages into a single sg entry.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
diff --git a/drivers/block/nvme.c b/drivers/block/nvme.c
index bfdca3a..c0e84b6 100644
--- a/drivers/block/nvme.c
+++ b/drivers/block/nvme.c
@@ -392,19 +392,25 @@
static int nvme_map_bio(struct device *dev, struct nvme_bio *nbio,
struct bio *bio, enum dma_data_direction dma_dir, int psegs)
{
- struct bio_vec *bvec;
- struct scatterlist *sg = nbio->sg;
- int i, nsegs;
+ struct bio_vec *bvec, *bvprv = NULL;
+ struct scatterlist *sg = NULL;
+ int i, nsegs = 0;
- sg_init_table(sg, psegs);
+ sg_init_table(nbio->sg, psegs);
bio_for_each_segment(bvec, bio, i) {
- sg_set_page(sg, bvec->bv_page, bvec->bv_len, bvec->bv_offset);
- sg++;
- /* XXX: handle non-mergable here */
- nsegs++;
+ if (bvprv && BIOVEC_PHYS_MERGEABLE(bvprv, bvec)) {
+ sg->length += bvec->bv_len;
+ } else {
+ /* Check bvprv && offset == 0 */
+ sg = sg ? sg + 1 : nbio->sg;
+ sg_set_page(sg, bvec->bv_page, bvec->bv_len,
+ bvec->bv_offset);
+ nsegs++;
+ }
+ bvprv = bvec;
}
nbio->nents = nsegs;
-
+ sg_mark_end(sg);
return dma_map_sg(dev, nbio->sg, nbio->nents, dma_dir);
}