| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 48/50] block: dont optimize for non-cloned bio in bio_get_last_bvec() | Date | Mon, 14 Mar 2016 10:51:06 -0700 |
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4.4-stable review patch. If anyone has any objections, please let me know.
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From: Ming Lei <ming.lei@canonical.com>
commit 90d0f0f11588ec692c12f9009089b398be395184 upstream.
For !BIO_CLONED bio, we can use .bi_vcnt safely, but it doesn't mean we can just simply return .bi_io_vec[.bi_vcnt - 1] because the start postion may have been moved in the middle of the bvec, such as splitting in the middle of bvec.
Fixes: 7bcd79ac50d9(block: bio: introduce helpers to get the 1st and last bvec) Reported-by: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- include/linux/bio.h | 5 ----- 1 file changed, 5 deletions(-)
--- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -320,11 +320,6 @@ static inline void bio_get_last_bvec(str struct bvec_iter iter = bio->bi_iter; int idx; - if (!bio_flagged(bio, BIO_CLONED)) { - *bv = bio->bi_io_vec[bio->bi_vcnt - 1]; - return; - } - if (unlikely(!bio_multiple_segments(bio))) { *bv = bio_iovec(bio); return;
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