[PATCH V4 23/45] fs/buffer.c: use bvec iterator to truncate the bio

[Ming Lei]

Once multipage bvec is enabled, the last bvec may include more than one
page, this patch use segment_last_page() to truncate the bio.

Signed-off-by: Ming Lei <ming....@redhat.com>
---
 fs/buffer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 8b26295a56fe..83fa7fda000b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3050,7 +3050,10 @@ void guard_bio_eod(int op, struct bio *bio)
 
        /* ..and clear the end of the buffer for reads */
        if (op == REQ_OP_READ) {
-               zero_user(bvec->bv_page, bvec->bv_offset + bvec->bv_len,
+               struct bio_vec bv;
+
+               segment_last_page(bvec, &bv);
+               zero_user(bv.bv_page, bv.bv_offset + bv.bv_len,
                                truncated_bytes);
        }
 }
-- 
2.9.5