nvmet: implement the changed namespaces log

Just keep a per-controller buffer of changed namespaces and copy it out
in the get log page implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index e96bb02c4f2c3b7bac33121c171c9569edacf60a..52129d13770e1bfe0c6a40f2d8f27731598d7bb5 100644 (file)
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -126,6 +126,29 @@ out:
        nvmet_req_complete(req, status);
 }
 
+static void nvmet_execute_get_log_changed_ns(struct nvmet_req *req)
+{
+       struct nvmet_ctrl *ctrl = req->sq->ctrl;
+       u16 status = NVME_SC_INTERNAL;
+       size_t len;
+
+       if (req->data_len != NVME_MAX_CHANGED_NAMESPACES * sizeof(__le32))
+               goto out;
+
+       mutex_lock(&ctrl->lock);
+       if (ctrl->nr_changed_ns == U32_MAX)
+               len = sizeof(__le32);
+       else
+               len = ctrl->nr_changed_ns * sizeof(__le32);
+       status = nvmet_copy_to_sgl(req, 0, ctrl->changed_ns_list, len);
+       if (!status)
+               status = nvmet_zero_sgl(req, len, req->data_len - len);
+       ctrl->nr_changed_ns = 0;
+       mutex_unlock(&ctrl->lock);
+out:
+       nvmet_req_complete(req, status);
+}
+
 static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
 {
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
@@ -543,6 +566,9 @@ u16 nvmet_parse_admin_cmd(struct nvmet_req *req)
                         */
                        req->execute = nvmet_execute_get_log_page_noop;
                        return 0;
+               case NVME_LOG_CHANGED_NS:
+                       req->execute = nvmet_execute_get_log_changed_ns;
+                       return 0;
                }
                break;
        case nvme_admin_identify:

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 55c4bc693aa2ff6514bbf0e17fd74d456cb129e6..4fe88e15c64126160d0110818aba9e0e5dd55bfa 100644 (file)
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -144,6 +144,42 @@ static void nvmet_add_async_event(struct nvmet_ctrl *ctrl, u8 event_type,
        schedule_work(&ctrl->async_event_work);
 }
 
+static void nvmet_add_to_changed_ns_log(struct nvmet_ctrl *ctrl, __le32 nsid)
+{
+       u32 i;
+
+       mutex_lock(&ctrl->lock);
+       if (ctrl->nr_changed_ns > NVME_MAX_CHANGED_NAMESPACES)
+               goto out_unlock;
+
+       for (i = 0; i < ctrl->nr_changed_ns; i++) {
+               if (ctrl->changed_ns_list[i] == nsid)
+                       goto out_unlock;
+       }
+
+       if (ctrl->nr_changed_ns == NVME_MAX_CHANGED_NAMESPACES) {
+               ctrl->changed_ns_list[0] = cpu_to_le32(0xffffffff);
+               ctrl->nr_changed_ns = U32_MAX;
+               goto out_unlock;
+       }
+
+       ctrl->changed_ns_list[ctrl->nr_changed_ns++] = nsid;
+out_unlock:
+       mutex_unlock(&ctrl->lock);
+}
+
+static void nvmet_ns_changed(struct nvmet_subsys *subsys, u32 nsid)
+{
+       struct nvmet_ctrl *ctrl;
+
+       list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+               nvmet_add_to_changed_ns_log(ctrl, cpu_to_le32(nsid));
+               nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE,
+                               NVME_AER_NOTICE_NS_CHANGED,
+                               NVME_LOG_CHANGED_NS);
+       }
+}
+
 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops)
 {
        int ret = 0;
@@ -287,7 +323,6 @@ static void nvmet_ns_dev_disable(struct nvmet_ns *ns)
 int nvmet_ns_enable(struct nvmet_ns *ns)
 {
        struct nvmet_subsys *subsys = ns->subsys;
-       struct nvmet_ctrl *ctrl;
        int ret = 0;
 
        mutex_lock(&subsys->lock);
@@ -326,9 +361,7 @@ int nvmet_ns_enable(struct nvmet_ns *ns)
                list_add_tail_rcu(&ns->dev_link, &old->dev_link);
        }
 
-       list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
-               nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE, 0, 0);
-
+       nvmet_ns_changed(subsys, ns->nsid);
        ns->enabled = true;
        ret = 0;
 out_unlock:
@@ -342,7 +375,6 @@ out_dev_put:
 void nvmet_ns_disable(struct nvmet_ns *ns)
 {
        struct nvmet_subsys *subsys = ns->subsys;
-       struct nvmet_ctrl *ctrl;
 
        mutex_lock(&subsys->lock);
        if (!ns->enabled)
@@ -368,9 +400,7 @@ void nvmet_ns_disable(struct nvmet_ns *ns)
        percpu_ref_exit(&ns->ref);
 
        mutex_lock(&subsys->lock);
-       list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
-               nvmet_add_async_event(ctrl, NVME_AER_TYPE_NOTICE, 0, 0);
-
+       nvmet_ns_changed(subsys, ns->nsid);
        nvmet_ns_dev_disable(ns);
 out_unlock:
        mutex_unlock(&subsys->lock);
@@ -832,11 +862,16 @@ u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
        kref_init(&ctrl->ref);
        ctrl->subsys = subsys;
 
+       ctrl->changed_ns_list = kmalloc_array(NVME_MAX_CHANGED_NAMESPACES,
+                       sizeof(__le32), GFP_KERNEL);
+       if (!ctrl->changed_ns_list)
+               goto out_free_ctrl;
+
        ctrl->cqs = kcalloc(subsys->max_qid + 1,
                        sizeof(struct nvmet_cq *),
                        GFP_KERNEL);
        if (!ctrl->cqs)
-               goto out_free_ctrl;
+               goto out_free_changed_ns_list;
 
        ctrl->sqs = kcalloc(subsys->max_qid + 1,
                        sizeof(struct nvmet_sq *),
@@ -894,6 +929,8 @@ out_free_sqs:
        kfree(ctrl->sqs);
 out_free_cqs:
        kfree(ctrl->cqs);
+out_free_changed_ns_list:
+       kfree(ctrl->changed_ns_list);
 out_free_ctrl:
        kfree(ctrl);
 out_put_subsystem:
@@ -920,6 +957,7 @@ static void nvmet_ctrl_free(struct kref *ref)
 
        kfree(ctrl->sqs);
        kfree(ctrl->cqs);
+       kfree(ctrl->changed_ns_list);
        kfree(ctrl);
 
        nvmet_subsys_put(subsys);

diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 768abe203298438ac1f983053f7bf660b1fd3059..8cdc1e550396c93b7932fa9a9073fd3c529b4ba5 100644 (file)
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -135,6 +135,9 @@ struct nvmet_ctrl {
 
        const struct nvmet_fabrics_ops *ops;
 
+       __le32                  *changed_ns_list;
+       u32                     nr_changed_ns;
+
        char                    subsysnqn[NVMF_NQN_FIELD_LEN];
        char                    hostnqn[NVMF_NQN_FIELD_LEN];
 };