On 3/4/23 01:13, Ming Lei wrote:
When investigating one customer report on warning in nvme_setup_discard, we observed the controller(nvme/tcp) actually exposes queue_max_discard_segments(req->q) == 1. Obviously the current code can't handle this situation, since contiguity merge like normal RW request is taken. Fix the issue by building range from request sector/nr_sectors directly. Fixes: b35ba01ea697 ("nvme: support ranged discard requests") Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- drivers/nvme/host/core.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index c2730b116dc6..d4be525f8100 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -781,16 +781,26 @@ static blk_status_t nvme_setup_discard(struct nvme_ns *ns, struct request *req, range = page_address(ns->ctrl->discard_page); }- __rq_for_each_bio(bio, req) {- u64 slba = nvme_sect_to_lba(ns, bio->bi_iter.bi_sector); - u32 nlb = bio->bi_iter.bi_size >> ns->lba_shift; - - if (n < segments) { - range[n].cattr = cpu_to_le32(0); - range[n].nlb = cpu_to_le32(nlb); - range[n].slba = cpu_to_le64(slba); + if (queue_max_discard_segments(req->q) == 1) { + u64 slba = nvme_sect_to_lba(ns, blk_rq_pos(req)); + u32 nlb = blk_rq_sectors(req) >> (ns->lba_shift - 9); + + range[0].cattr = cpu_to_le32(0); + range[0].nlb = cpu_to_le32(nlb); + range[0].slba = cpu_to_le64(slba); + n = 1; + } else { + __rq_for_each_bio(bio, req) { + u64 slba = nvme_sect_to_lba(ns, bio->bi_iter.bi_sector); + u32 nlb = bio->bi_iter.bi_size >> ns->lba_shift; + + if (n < segments) { + range[n].cattr = cpu_to_le32(0); + range[n].nlb = cpu_to_le32(nlb); + range[n].slba = cpu_to_le64(slba); + } + n++; } - n++; }if (WARN_ON_ONCE(n != segments)) {
Maybe just set segments to min(blk_rq_nr_discard_segments(req), queue_max_discard_segments(req->q)) and let the existing code do
its thing?
