[BLOCK] Clear sg entry before filling in blk_rq_map_sg()
The memset() of the sg entry was originally removed, because it could
overwrite a chain pointer. But it's quite OK to memset() it when we know
it's a valid entry, since it can't contain a chain pointer.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index 9eabac9..1014d34 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1352,6 +1352,7 @@
sg = next_sg;
next_sg = sg_next(sg);
+ memset(sg, 0, sizeof(*sg));
sg->page = bvec->bv_page;
sg->length = nbytes;
sg->offset = bvec->bv_offset;