[PATCH 1/3] block: improve the gap check in __bio_add_pc_page
From: Christoph Hellwig <hch@lst.de>
Date: 2019-08-12 15:40:05
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
If we can add more data into an existing segment we do not create a gap per definition, so move the check for a gap after the attempt to merge into the segment. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <redacted> --- block/bio.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 24a496f5d2e2..9f80bf4531b3 100644
--- a/block/bio.c
+++ b/block/bio.c@@ -710,18 +710,18 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio, goto done; } - /* - * If the queue doesn't support SG gaps and adding this - * offset would create a gap, disallow it. - */ - if (bvec_gap_to_prev(q, bvec, offset)) - return 0; - if (page_is_mergeable(bvec, page, len, offset, &same_page) && can_add_page_to_seg(q, bvec, page, len, offset)) { bvec->bv_len += len; goto done; } + + /* + * If the queue doesn't support SG gaps and adding this segment + * would create a gap, disallow it. + */ + if (bvec_gap_to_prev(q, bvec, offset)) + return 0; } if (bio_full(bio, len))
--
2.20.1