This allows bio splits in the middle of a vector to form the largest possible bio at the h/w's desired alignment, and guarantees the bio being split will have some data. Previously, if the first vector's length was greater than the allowable amount, the bio would split at a zero length and hit a kernel BUG. The length check is moved after the SG_GAPS check so that check doesn't need to be duplicated in the split case. Fixes: d3805611130af9b911e908af9f67a3f64f4f0914 bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=110231 Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx> --- block/blk-merge.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index e73846a..e886a7d 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -81,9 +81,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, struct bio *new = NULL; bio_for_each_segment(bv, bio, iter) { - if (sectors + (bv.bv_len >> 9) > blk_max_size_offset(q, bio->bi_iter.bi_sector)) - goto split; - /* * If the queue doesn't support SG gaps and adding this * offset would create a gap, disallow it. @@ -91,6 +88,17 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, if (bvprvp && bvec_gap_to_prev(q, bvprvp, bv.bv_offset)) goto split; + if (sectors + (bv.bv_len >> 9) > blk_max_size_offset(q, bio->bi_iter.bi_sector)) { + /* + * Consider this a new segment if we're taking any part + * of this vector. + */ + if (sectors < blk_max_size_offset(q, bio->bi_iter.bi_sector)) + ++nsegs; + sectors = blk_max_size_offset(q, bio->bi_iter.bi_sector); + goto split; + } + if (bvprvp && blk_queue_cluster(q)) { if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; -- 2.6.2.307.g37023ba -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
