Commit b59ea3ef authored by Ming Lei's avatar Ming Lei Committed by Greg Kroah-Hartman

block: don't optimize for non-cloned bio in bio_get_last_bvec()

commit 90d0f0f1 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: 7bcd79ac(block: bio: introduce helpers to get the 1st and last bvec)
Reported-by: default avatarKent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: default avatarMing Lei <ming.lei@canonical.com>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a2cee580
......@@ -320,11 +320,6 @@ static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
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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