From 5e063101ffacf7c14797f5185c58a967ca83c79f Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Fri, 16 Oct 2020 16:19:05 -0600 Subject: nvmet: cleanup nvmet_passthru_map_sg() Clean up some confusing elements of nvmet_passthru_map_sg() by returning early if the request is greater than the maximum bio size. This allows us to drop the sg_cnt variable. This should not result in any functional change but makes the code clearer and more understandable. The original code allocated a truncated bio then would return EINVAL when bio_add_pc_page() filled that bio. The new code just returns EINVAL early if this would happen. Fixes: c1fef73f793b ("nvmet: add passthru code to process commands") Signed-off-by: Logan Gunthorpe Suggested-by: Douglas Gilbert Reviewed-by: Sagi Grimberg Cc: Christoph Hellwig Cc: Chaitanya Kulkarni Signed-off-by: Christoph Hellwig --- drivers/nvme/target/passthru.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/nvme') diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c index 323046e1d67f..0814cba8298a 100644 --- a/drivers/nvme/target/passthru.c +++ b/drivers/nvme/target/passthru.c @@ -187,18 +187,20 @@ static void nvmet_passthru_req_done(struct request *rq, static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq) { - int sg_cnt = req->sg_cnt; struct scatterlist *sg; int op_flags = 0; struct bio *bio; int i, ret; + if (req->sg_cnt > BIO_MAX_PAGES) + return -EINVAL; + if (req->cmd->common.opcode == nvme_cmd_flush) op_flags = REQ_FUA; else if (nvme_is_write(req->cmd)) op_flags = REQ_SYNC | REQ_IDLE; - bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES)); + bio = bio_alloc(GFP_KERNEL, req->sg_cnt); bio->bi_end_io = bio_put; bio->bi_opf = req_op(rq) | op_flags; @@ -208,7 +210,6 @@ static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq) bio_put(bio); return -EINVAL; } - sg_cnt--; } ret = blk_rq_append_bio(rq, &bio); -- cgit v1.2.3