[PATCH 5.10 055/102] nvme: split nvme_alloc_request()

From: Greg Kroah-Hartman
Date: Mon Jun 27 2022 - 07:26:18 EST


From: Chaitanya Kulkarni <chaitanya.kulkarni@xxxxxxx>

[ Upstream commit 39dfe84451b4526a8054cc5a127337bca980dfa3 ]

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@xxxxxxx>
Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nvme/host/core.c | 52 +++++++++++++++++++++++-----------
drivers/nvme/host/lightnvm.c | 5 ++--
drivers/nvme/host/nvme.h | 2 ++
drivers/nvme/host/pci.c | 4 +--
drivers/nvme/target/passthru.c | 2 +-
5 files changed, 42 insertions(+), 23 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 4a7154cbca50..68395dcd067c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -538,21 +538,14 @@ static inline void nvme_clear_nvme_request(struct request *req)
}
}

-struct request *nvme_alloc_request(struct request_queue *q,
- struct nvme_command *cmd, blk_mq_req_flags_t flags, int qid)
+static inline unsigned int nvme_req_op(struct nvme_command *cmd)
{
- unsigned op = nvme_is_write(cmd) ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN;
- struct request *req;
-
- if (qid == NVME_QID_ANY) {
- req = blk_mq_alloc_request(q, op, flags);
- } else {
- req = blk_mq_alloc_request_hctx(q, op, flags,
- qid ? qid - 1 : 0);
- }
- if (IS_ERR(req))
- return req;
+ return nvme_is_write(cmd) ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN;
+}

+static inline void nvme_init_request(struct request *req,
+ struct nvme_command *cmd)
+{
if (req->q->queuedata)
req->timeout = NVME_IO_TIMEOUT;
else /* no queuedata implies admin queue */
@@ -561,11 +554,33 @@ struct request *nvme_alloc_request(struct request_queue *q,
req->cmd_flags |= REQ_FAILFAST_DRIVER;
nvme_clear_nvme_request(req);
nvme_req(req)->cmd = cmd;
+}

+struct request *nvme_alloc_request(struct request_queue *q,
+ struct nvme_command *cmd, blk_mq_req_flags_t flags)
+{
+ struct request *req;
+
+ req = blk_mq_alloc_request(q, nvme_req_op(cmd), flags);
+ if (!IS_ERR(req))
+ nvme_init_request(req, cmd);
return req;
}
EXPORT_SYMBOL_GPL(nvme_alloc_request);

+struct request *nvme_alloc_request_qid(struct request_queue *q,
+ struct nvme_command *cmd, blk_mq_req_flags_t flags, int qid)
+{
+ struct request *req;
+
+ req = blk_mq_alloc_request_hctx(q, nvme_req_op(cmd), flags,
+ qid ? qid - 1 : 0);
+ if (!IS_ERR(req))
+ nvme_init_request(req, cmd);
+ return req;
+}
+EXPORT_SYMBOL_GPL(nvme_alloc_request_qid);
+
static int nvme_toggle_streams(struct nvme_ctrl *ctrl, bool enable)
{
struct nvme_command c;
@@ -928,7 +943,10 @@ int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
struct request *req;
int ret;

- req = nvme_alloc_request(q, cmd, flags, qid);
+ if (qid == NVME_QID_ANY)
+ req = nvme_alloc_request(q, cmd, flags);
+ else
+ req = nvme_alloc_request_qid(q, cmd, flags, qid);
if (IS_ERR(req))
return PTR_ERR(req);

@@ -1099,7 +1117,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
void *meta = NULL;
int ret;

- req = nvme_alloc_request(q, cmd, 0, NVME_QID_ANY);
+ req = nvme_alloc_request(q, cmd, 0);
if (IS_ERR(req))
return PTR_ERR(req);

@@ -1174,8 +1192,8 @@ static int nvme_keep_alive(struct nvme_ctrl *ctrl)
{
struct request *rq;

- rq = nvme_alloc_request(ctrl->admin_q, &ctrl->ka_cmd, BLK_MQ_REQ_RESERVED,
- NVME_QID_ANY);
+ rq = nvme_alloc_request(ctrl->admin_q, &ctrl->ka_cmd,
+ BLK_MQ_REQ_RESERVED);
if (IS_ERR(rq))
return PTR_ERR(rq);

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 88a7c8eac455..470cef3abec3 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -653,7 +653,7 @@ static struct request *nvme_nvm_alloc_request(struct request_queue *q,

nvme_nvm_rqtocmd(rqd, ns, cmd);

- rq = nvme_alloc_request(q, (struct nvme_command *)cmd, 0, NVME_QID_ANY);
+ rq = nvme_alloc_request(q, (struct nvme_command *)cmd, 0);
if (IS_ERR(rq))
return rq;

@@ -767,8 +767,7 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
DECLARE_COMPLETION_ONSTACK(wait);
int ret = 0;

- rq = nvme_alloc_request(q, (struct nvme_command *)vcmd, 0,
- NVME_QID_ANY);
+ rq = nvme_alloc_request(q, (struct nvme_command *)vcmd, 0);
if (IS_ERR(rq)) {
ret = -ENOMEM;
goto err_cmd;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 95b9657cabaf..8e40a6306e53 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -662,6 +662,8 @@ 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,
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f2d0148d4050..07a4d5d387cd 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1350,7 +1350,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
req->tag, nvmeq->qid);

abort_req = nvme_alloc_request(dev->ctrl.admin_q, &cmd,
- BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
+ BLK_MQ_REQ_NOWAIT);
if (IS_ERR(abort_req)) {
atomic_inc(&dev->ctrl.abort_limit);
return BLK_EH_RESET_TIMER;
@@ -2278,7 +2278,7 @@ static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
cmd.delete_queue.opcode = opcode;
cmd.delete_queue.qid = cpu_to_le16(nvmeq->qid);

- req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT, NVME_QID_ANY);
+ req = nvme_alloc_request(q, &cmd, BLK_MQ_REQ_NOWAIT);
if (IS_ERR(req))
return PTR_ERR(req);

diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index 8ee94f056898..d24251ece502 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -244,7 +244,7 @@ static void nvmet_passthru_execute_cmd(struct nvmet_req *req)
q = ns->queue;
}

- rq = nvme_alloc_request(q, req->cmd, 0, NVME_QID_ANY);
+ rq = nvme_alloc_request(q, req->cmd, 0);
if (IS_ERR(rq)) {
status = NVME_SC_INTERNAL;
goto out_put_ns;
--
2.35.1