admin-cmd: Added smart-log command support.

This patch implements the support for smart-log command
(NVM Express 1.2.1-section 5.10.1.2 SMART / Health Information
(Log Identifier 02h)) on the target for NVMe over Fabric.

In current implementation host can retrieve following statistics:-
1. Data Units Read.
2. Data Units Written.
3. Host Read Commands.
4. Host Write Commands.

Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index 47c564b5a2895198b020a26851b824350f10006e..7ab9c9381b989578cb5faaf6054721ace331c631 100644 (file)
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -14,6 +14,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 #include <linux/module.h>
 #include <generated/utsrelease.h>
+#include <asm/unaligned.h>
 #include "nvmet.h"
 
 u32 nvmet_get_log_page_len(struct nvme_command *cmd)
@@ -29,8 +30,84 @@ u32 nvmet_get_log_page_len(struct nvme_command *cmd)
        return len;
 }
 
+static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
+               struct nvme_smart_log *slog)
+{
+       u16 status;
+       struct nvmet_ns *ns;
+       u64 host_reads, host_writes, data_units_read, data_units_written;
+
+       status = NVME_SC_SUCCESS;
+       ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->get_log_page.nsid);
+       if (!ns) {
+               status = NVME_SC_INVALID_NS;
+               pr_err("nvmet : Counld not find namespace id : %d\n",
+                               le32_to_cpu(req->cmd->get_log_page.nsid));
+               goto out;
+       }
+
+       host_reads = part_stat_read(ns->bdev->bd_part, ios[READ]);
+       data_units_read = part_stat_read(ns->bdev->bd_part, sectors[READ]);
+       host_writes = part_stat_read(ns->bdev->bd_part, ios[WRITE]);
+       data_units_written = part_stat_read(ns->bdev->bd_part, sectors[WRITE]);
+
+       put_unaligned_le64(host_reads, &slog->host_reads[0]);
+       put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
+       put_unaligned_le64(host_writes, &slog->host_writes[0]);
+       put_unaligned_le64(data_units_written, &slog->data_units_written[0]);
+       nvmet_put_namespace(ns);
+out:
+       return status;
+}
+
+static u16 nvmet_get_smart_log_all(struct nvmet_req *req,
+               struct nvme_smart_log *slog)
+{
+       u16 status;
+       u64 host_reads = 0, host_writes = 0;
+       u64 data_units_read = 0, data_units_written = 0;
+       struct nvmet_ns *ns;
+       struct nvmet_ctrl *ctrl;
+
+       status = NVME_SC_SUCCESS;
+       ctrl = req->sq->ctrl;
+
+       rcu_read_lock();
+       list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
+               host_reads += part_stat_read(ns->bdev->bd_part, ios[READ]);
+               data_units_read +=
+                       part_stat_read(ns->bdev->bd_part, sectors[READ]);
+               host_writes += part_stat_read(ns->bdev->bd_part, ios[WRITE]);
+               data_units_written +=
+                       part_stat_read(ns->bdev->bd_part, sectors[WRITE]);
+
+       }
+       rcu_read_unlock();
+
+       put_unaligned_le64(host_reads, &slog->host_reads[0]);
+       put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
+       put_unaligned_le64(host_writes, &slog->host_writes[0]);
+       put_unaligned_le64(data_units_written, &slog->data_units_written[0]);
+
+       return status;
+}
+
+static u16 nvmet_get_smart_log(struct nvmet_req *req,
+               struct nvme_smart_log *slog)
+{
+       u16 status;
+
+       WARN_ON(req == NULL || slog == NULL);
+       if (req->cmd->get_log_page.nsid == 0xFFFFFFFF)
+               status = nvmet_get_smart_log_all(req, slog);
+       else
+               status = nvmet_get_smart_log_nsid(req, slog);
+       return status;
+}
+
 static void nvmet_execute_get_log_page(struct nvmet_req *req)
 {
+       struct nvme_smart_log *smart_log;
        size_t data_len = nvmet_get_log_page_len(req->cmd);
        void *buf;
        u16 status = 0;
@@ -59,6 +136,16 @@ static void nvmet_execute_get_log_page(struct nvmet_req *req)
                 * available (e.g. units or commands read/written) those aren't
                 * persistent over power loss.
                 */
+               if (data_len != sizeof(*smart_log)) {
+                       status = NVME_SC_INTERNAL;
+                       goto err;
+               }
+               smart_log = buf;
+               status = nvmet_get_smart_log(req, smart_log);
+               if (status) {
+                       memset(buf, '\0', data_len);
+                       goto err;
+               }
                break;
        case 0x03:
                /*
@@ -73,6 +160,7 @@ static void nvmet_execute_get_log_page(struct nvmet_req *req)
 
        status = nvmet_copy_to_sgl(req, 0, buf, data_len);
 
+err:
        kfree(buf);
 out:
        nvmet_req_complete(req, status);