block: fix segment split

Inside blk_bio_segment_split(), previous bvec pointer(bvprvp)
always points to the iterator local variable, which is obviously
wrong, so fix it by pointing to the local variable of 'bvprv'.

Fixes: 5014c311baa2b(block: fix bogus compiler warnings in blk-merge.c)
Cc: stable@kernel.org #4.3
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Reported-by: Mark Salter <msalter@redhat.com>
Tested-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

diff --git a/block/blk-merge.c b/block/blk-merge.c
index de5716d..f2efe8a 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -98,7 +98,7 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 
                        seg_size += bv.bv_len;
                        bvprv = bv;
-                       bvprvp = &bv;
+                       bvprvp = &bvprv;
                        sectors += bv.bv_len >> 9;
                        continue;
                }
@@ -108,7 +108,7 @@ new_segment:
 
                nsegs++;
                bvprv = bv;
-               bvprvp = &bv;
+               bvprvp = &bvprv;
                seg_size = bv.bv_len;
                sectors += bv.bv_len >> 9;
        }