[PATCH v1 05/54] fs/buffer: comment on direct access to bvec table

From	Ming Lei <tom.leiming@gmail.com>
Newsgroups	linux.kernel
Subject	[PATCH v1 05/54] fs/buffer: comment on direct access to bvec table
Date	2016-12-27 17:10 +0100
Message-ID	<sT2u7-4eA-81@gated-at.bofh.it> (permalink)
References	<sT2u5-4eA-3@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 fs/buffer.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index d21771fcf7d3..63d2f40c21fd 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3060,8 +3060,13 @@ static void end_bio_bh_io_sync(struct bio *bio)
 void guard_bio_eod(int op, struct bio *bio)
 {
 	sector_t maxsector;
-	struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
 	unsigned truncated_bytes;
+	/*
+	 * It is safe to truncate the last bvec in the following way
+	 * even though multipage bvec is supported, but we need to
+	 * fix the parameters passed to zero_user().
+	 */
+	struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
 
 	maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9;
 	if (!maxsector)
-- 
2.7.4

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[PATCH v1 05/54] fs/buffer: comment on direct access to bvec table Ming Lei <tom.leiming@gmail.com> - 2016-12-27 17:10 +0100

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