nvme: split nvme_alloc_request()
Right now nvme_alloc_request() allocates a request from block layer
based on the value of the qid. When qid set to NVME_QID_ANY it used
blk_mq_alloc_request() else blk_mq_alloc_request_hctx().
The function nvme_alloc_request() is called from different context, The
only place where it uses non NVME_QID_ANY value is for fabrics connect
commands :-
nvme_submit_sync_cmd() NVME_QID_ANY
nvme_features() NVME_QID_ANY
nvme_sec_submit() NVME_QID_ANY
nvmf_reg_read32() NVME_QID_ANY
nvmf_reg_read64() NVME_QID_ANY
nvmf_reg_write32() NVME_QID_ANY
nvmf_connect_admin_queue() NVME_QID_ANY
nvme_submit_user_cmd() NVME_QID_ANY
nvme_alloc_request()
nvme_keep_alive() NVME_QID_ANY
nvme_alloc_request()
nvme_timeout() NVME_QID_ANY
nvme_alloc_request()
nvme_delete_queue() NVME_QID_ANY
nvme_alloc_request()
nvmet_passthru_execute_cmd() NVME_QID_ANY
nvme_alloc_request()
nvmf_connect_io_queue() QID
__nvme_submit_sync_cmd()
nvme_alloc_request()
With passthru nvme_alloc_request() now falls into the I/O fast path such
that blk_mq_alloc_request_hctx() is never gets called and that adds
additional branch check in fast path.
Split the nvme_alloc_request() into nvme_alloc_request() and
nvme_alloc_request_qid().
Replace each call of the nvme_alloc_request() with NVME_QID_ANY param
with a call to newly added nvme_alloc_request() without NVME_QID_ANY.
Replace a call to nvme_alloc_request() with QID param with a call to
newly added nvme_alloc_request() and nvme_alloc_request_qid()
based on the qid value set in the __nvme_submit_sync_cmd().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 824776a..83fb30e 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -611,6 +611,8 @@ void nvme_start_freeze(struct nvme_ctrl *ctrl);
#define NVME_QID_ANY -1
struct request *nvme_alloc_request(struct request_queue *q,
+ struct nvme_command *cmd, blk_mq_req_flags_t flags);
+struct request *nvme_alloc_request_qid(struct request_queue *q,
struct nvme_command *cmd, blk_mq_req_flags_t flags, int qid);
void nvme_cleanup_cmd(struct request *req);
blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req,