On 04/28/2015 04:43 AM, Christoph Hellwig wrote: > This seems to lack support for QUEUE_FLAG_SG_GAPS to work around > the retarded PPR format in the NVMe driver. I'm actually not > sure we have a way to reproduce them for BLOCK_PC requests, but I think > we should make sure to properly handle them. How about below incremental patch? block/bio.c | 8 -------- block/blk-merge.c | 8 ++++++++ 2 files changed, 8 insertions(+), 8 deletions(-) diff --git a/block/bio.c b/block/bio.c index ae31cdb..3f6bd9a 100644 --- a/block/bio.c +++ b/block/bio.c @@ -743,14 +743,6 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page bio->bi_iter.bi_size += len; goto done; } - - /* - * If the queue doesn't support SG gaps and adding this - * offset would create a gap, disallow it. - */ - if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && - bvec_gap_to_prev(prev, offset)) - return 0; } if (bio->bi_vcnt >= bio->bi_max_vecs) diff --git a/block/blk-merge.c b/block/blk-merge.c index 9d565a0..32f6d6c 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -78,6 +78,14 @@ static struct bio *blk_bio_segment_split(struct request_queue *q, if (sectors > queue_max_sectors(q)) goto split; + /* + * If the queue doesn't support SG gaps and adding this + * offset would create a gap, disallow it. + */ + if (q->queue_flags & (1 << QUEUE_FLAG_SG_GAPS) && + prev && bvec_gap_to_prev(&bvprv, bv.bv_offset)) + goto split; + if (prev && blk_queue_cluster(q)) { if (seg_size + bv.bv_len > queue_max_segment_size(q)) goto new_segment; -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel