Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Ming Lei <ming.lei@redhat.com>
To:     Jens Axboe <axboe@fb.com>, Christoph Hellwig <hch@infradead.org>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Kent Overstreet <kent.overstreet@gmail.com>
Cc:     David Sterba <dsterba@suse.cz>, Huang Ying <ying.huang@intel.com>,
        linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
        Theodore Ts'o <tytso@mit.edu>,
        "Darrick J . Wong" <darrick.wong@oracle.com>,
        Coly Li <colyli@suse.de>, Filipe Manana <fdmanana@gmail.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        Ming Lei <ming.lei@redhat.com>
Subject: [PATCH V6 09/30] fs/buffer.c: use bvec iterator to truncate the bio
Date:   Sat,  9 Jun 2018 20:29:53 +0800
Message-Id: <20180609123014.8861-10-ming.lei@redhat.com>
In-Reply-To: <20180609123014.8861-1-ming.lei@redhat.com>
References: <20180609123014.8861-1-ming.lei@redhat.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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

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

diff --git a/fs/buffer.c b/fs/buffer.c
index cabc045f483d..630ae3e0238b 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3021,7 +3021,10 @@ 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;
+
+		chunk_last_segment(bvec, &bv);
+		zero_user(bv.bv_page, bv.bv_offset + bv.bv_len,
 				truncated_bytes);
 	}
 }
-- 
2.9.5