[PATCH V3 03/11] nvmet: make nvmet_find_namespace() req based

Chaitanya Kulkarni
2021-02-10T05:48:45Z

The six callers of nvmet_find_namespace() duplicate the error log page
update and status setting code for each call on failure.

All callers are nvmet requests based functions, so we can pass req
to the nvmet_find_namesapce() & derive ctrl from req, that'll allow us
to update the error log page in nvmet_find_namespace(). Now that we
pass the request we can also get rid of the local variable in
nvmet_find_namespace() and use the req->ns and return the error code.

Replace the ctrl parameter with nvmet_req for nvmet_find_namespace(),
centralize the error log page update for non allocated namesapces, and
return uniform error for non-allocated namespace.

The nvmet_find_namespace() takes nsid parameter which is from NVMe
commands structures such as get_log_page, identify, rw and common. All
these commands have same offset for the nsid field.

Derive nsid from req->cmd->common.nsid) & remove the extra parameter
from the nvmet_find_namespace().

Lastly now we associate the ns to the req parameter that we pass to the
nvmet_find_namespace(), rename the nvmet_find_namespace() to
nvmet_req_find_ns() i.e. :-

Old:-
struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl,
__le32 nsid)
New :-
u16 nvmet_req_find_ns(struct nvmet_req *req);

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
---
drivers/nvme/target/admin-cmd.c | 46 +++++++++++++--------------------
drivers/nvme/target/core.c | 24 +++++++++--------
drivers/nvme/target/nvmet.h | 2 +-
3 files changed, 32 insertions(+), 40 deletions(-)

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index e938064254a5..f32533480e66 100644
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -75,15 +75,11 @@ static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
struct nvme_smart_log *slog)
{
u64 host_reads, host_writes, data_units_read, data_units_written;
+ u16 status;

- req->ns = nvmet_find_namespace(req->sq->ctrl,
- req->cmd->get_log_page.nsid);
- if (!req->ns) {
- pr_err("Could not find namespace id : %d\n",
- le32_to_cpu(req->cmd->get_log_page.nsid));
- req->error_loc = offsetof(struct nvme_rw_command, nsid);
- return NVME_SC_INVALID_NS | NVME_SC_DNR;
- }
+ status = nvmet_req_find_ns(req);
+ if (status)
+ return status;

/* we don't have the right data for file backed ns */
if (!req->ns->bdev)
@@ -468,7 +464,7 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
{
struct nvmet_ctrl *ctrl = req->sq->ctrl;
struct nvme_id_ns *id;
- u16 status = 0;
+ u16 status;

if (le32_to_cpu(req->cmd->identify.nsid) == NVME_NSID_ALL) {
req->error_loc = offsetof(struct nvme_identify, nsid);
@@ -483,8 +479,8 @@ static void nvmet_execute_identify_ns(struct nvmet_req *req)
}

/* return an all zeroed buffer if we can't find an active namespace */
- req->ns = nvmet_find_namespace(ctrl, req->cmd->identify.nsid);
- if (!req->ns) {
+ status = nvmet_req_find_ns(req);
+ if (status) {
status = 0;
goto done;
}
@@ -604,15 +600,12 @@ static u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,

static void nvmet_execute_identify_desclist(struct nvmet_req *req)
{
- u16 status = 0;
off_t off = 0;
+ u16 status;

- req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->identify.nsid);
- if (!req->ns) {
- req->error_loc = offsetof(struct nvme_identify, nsid);
- status = NVME_SC_INVALID_NS | NVME_SC_DNR;
+ status = nvmet_req_find_ns(req);
+ if (status)
goto out;
- }

if (memchr_inv(&req->ns->uuid, 0, sizeof(req->ns->uuid))) {
status = nvmet_copy_ns_identifier(req, NVME_NIDT_UUID,
@@ -692,13 +685,11 @@ static u16 nvmet_set_feat_write_protect(struct nvmet_req *req)
{
u32 write_protect = le32_to_cpu(req->cmd->common.cdw11);
struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
- u16 status = NVME_SC_FEATURE_NOT_CHANGEABLE;
+ u16 status;

- req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->rw.nsid);
- if (unlikely(!req->ns)) {
- req->error_loc = offsetof(struct nvme_common_command, nsid);
- return status = NVME_SC_INVALID_NS | NVME_SC_DNR;
- }
+ status = nvmet_req_find_ns(req);
+ if (status)
+ return status;

mutex_lock(&subsys->lock);
switch (write_protect) {
@@ -799,11 +790,10 @@ static u16 nvmet_get_feat_write_protect(struct nvmet_req *req)
struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
u32 result;

- req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->common.nsid);
- if (!req->ns) {
- req->error_loc = offsetof(struct nvme_common_command, nsid);
- return NVME_SC_INVALID_NS | NVME_SC_DNR;
- }
+ result = nvmet_req_find_ns(req);
+ if (result)
+ return result;
+
mutex_lock(&subsys->lock);
if (req->ns->readonly == true)
result = NVME_NS_WRITE_PROTECT;
diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 8ce4d59cc9e7..95b58d4b1af2 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -417,15 +417,18 @@ void nvmet_stop_keep_alive_timer(struct nvmet_ctrl *ctrl)
cancel_delayed_work_sync(&ctrl->ka_work);
}

-struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid)
+u16 nvmet_req_find_ns(struct nvmet_req *req)
{
- struct nvmet_ns *ns;
+ u32 nsid = le32_to_cpu(req->cmd->common.nsid);

- ns = xa_load(&ctrl->subsys->namespaces, le32_to_cpu(nsid));
- if (ns)
- percpu_ref_get(&ns->ref);
+ req->ns = xa_load(&req->sq->ctrl->subsys->namespaces, nsid);
+ if (unlikely(!req->ns)) {
+ req->error_loc = offsetof(struct nvme_common_command, nsid);
+ return NVME_SC_INVALID_NS | NVME_SC_DNR;
+ }

- return ns;
+ percpu_ref_get(&req->ns->ref);
+ return NVME_SC_SUCCESS;
}

static void nvmet_destroy_namespace(struct percpu_ref *ref)
@@ -862,11 +865,10 @@ static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
if (nvmet_req_passthru_ctrl(req))
return nvmet_parse_passthru_io_cmd(req);

- req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
- if (unlikely(!req->ns)) {
- req->error_loc = offsetof(struct nvme_common_command, nsid);
- return NVME_SC_INVALID_NS | NVME_SC_DNR;
- }
+ ret = nvmet_req_find_ns(req);
+ if (unlikely(ret))
+ return ret;
+
ret = nvmet_check_ana_state(req->port, req->ns);
if (unlikely(ret)) {
req->error_loc = offsetof(struct nvme_common_command, nsid);
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 8776dd1a0490..954b3d8451f5 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -443,7 +443,7 @@ struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
void nvmet_subsys_put(struct nvmet_subsys *subsys);
void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys);

-struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid);
+u16 nvmet_req_find_ns(struct nvmet_req *req);
void nvmet_put_namespace(struct nvmet_ns *ns);
int nvmet_ns_enable(struct nvmet_ns *ns);
void nvmet_ns_disable(struct nvmet_ns *ns);