Re: [PATCHv3 5/6] block/bounce: count bytes instead of sectors
From: Christoph Hellwig <hch@lst.de>
Date: 2022-05-24 06:09:28
Also in:
linux-fsdevel
On Mon, May 23, 2022 at 02:01:18PM -0700, Keith Busch wrote:
quoted hunk ↗ jump to hunk
From: Keith Busch <kbusch@kernel.org> Individual bv_len's may not be a sector size. Signed-off-by: Keith Busch <kbusch@kernel.org> --- block/bounce.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/block/bounce.c b/block/bounce.c index 8f7b6fe3b4db..20a43c4dbdda 100644 --- a/block/bounce.c +++ b/block/bounce.c@@ -207,17 +207,18 @@ void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) struct bvec_iter iter; unsigned i = 0; bool bounce = false; - int sectors = 0; + int sectors = 0, bytes = 0; bio_for_each_segment(from, *bio_orig, iter) { if (i++ < BIO_MAX_VECS) - sectors += from.bv_len >> 9; + bytes += from.bv_len; if (PageHighMem(from.bv_page)) bounce = true; } if (!bounce) return; + sectors = ALIGN_DOWN(bytes, queue_logical_block_size(q)) >> 9;
Same comment about SECTOR_SHIFT and a comment here. That being said, why do we even align here? Shouldn't bytes always be setor aligned here and this should be a WARN_ON or other sanity check? Probably the same for the previous patch.