From: Chaitanya Kulkarni chaitanya.kulkarni@wdc.com
[ Upstream commit c03fd85de293a4f65fcb94a795bf4c12a432bb6c ]
nvme_clear_request() has a check for flag REQ_DONTPREP and it is called from nvme_init_request() and nvme_setuo_cmd().
The function nvme_init_request() is called from nvme_alloc_request() and nvme_alloc_request_qid(). From these two callers new request is allocated everytime. For newly allocated request RQF_DONTPREP is never set. Since after getting a tag, block layer sets the req->rq_flags == 0 and never sets the REQ_DONTPREP when returning the request :-
nvme_alloc_request() blk_mq_alloc_request() blk_mq_rq_ctx_init() rq->rq_flags = 0 <----
nvme_alloc_request_qid() blk_mq_alloc_request_hctx() blk_mq_rq_ctx_init() rq->rq_flags = 0 <----
The block layer does set req->rq_flags but REQ_DONTPREP is not one of them and that is set by the driver.
That means we can unconditinally set the REQ_DONTPREP value to the rq->rq_flags when nvme_init_request()->nvme_clear_request() is called from above two callers.
Move the check for REQ_DONTPREP from nvme_clear_nvme_request() into nvme_setup_cmd().
This is needed since nvme_alloc_request() now gets called from fast path when NVMeOF target is configured with passthru backend to avoid unnecessary checks in the fast path.
Signed-off-by: Chaitanya Kulkarni chaitanya.kulkarni@wdc.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/core.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index d81b0cff15e0..c42ad0b8247b 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -531,11 +531,9 @@ EXPORT_SYMBOL_NS_GPL(nvme_put_ns, NVME_TARGET_PASSTHRU);
static inline void nvme_clear_nvme_request(struct request *req) { - if (!(req->rq_flags & RQF_DONTPREP)) { - nvme_req(req)->retries = 0; - nvme_req(req)->flags = 0; - req->rq_flags |= RQF_DONTPREP; - } + nvme_req(req)->retries = 0; + nvme_req(req)->flags = 0; + req->rq_flags |= RQF_DONTPREP; }
static inline unsigned int nvme_req_op(struct nvme_command *cmd) @@ -854,7 +852,8 @@ blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req, struct nvme_ctrl *ctrl = nvme_req(req)->ctrl; blk_status_t ret = BLK_STS_OK;
- nvme_clear_nvme_request(req); + if (!(req->rq_flags & RQF_DONTPREP)) + nvme_clear_nvme_request(req);
memset(cmd, 0, sizeof(*cmd)); switch (req_op(req)) {