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authorLogan Gunthorpe <logang@deltatee.com>2020-10-16 16:19:05 -0600
committerChristoph Hellwig <hch@lst.de>2020-10-22 15:28:02 +0200
commit5e063101ffacf7c14797f5185c58a967ca83c79f (patch)
tree9dd5d8300c7ec5af92fe15492027363d6ed7f370
parentdf06047d54276f73782c9d97882b305fca745d3f (diff)
downloadlinux-5e063101ffacf7c14797f5185c58a967ca83c79f.tar.bz2
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 <logang@deltatee.com> Suggested-by: Douglas Gilbert <dgilbert@interlog.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Cc: Christoph Hellwig <hch@lst.de> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
-rw-r--r--drivers/nvme/target/passthru.c7
1 files changed, 4 insertions, 3 deletions
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);