nvmet: add error log page cmd handler

Now that we have support for all the major parts of the target we add
a NVMe error log page handler so that host can read the log page.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/target/admin-cmd.c b/drivers/nvme/target/admin-cmd.c
index fa62db7a5e9e4127786161c814bbe2076905c804..00956b4106a8c510e80205a63388ea9322a4acd6 100644 (file)
--- a/drivers/nvme/target/admin-cmd.c
+++ b/drivers/nvme/target/admin-cmd.c
@@ -37,6 +37,34 @@ static void nvmet_execute_get_log_page_noop(struct nvmet_req *req)
        nvmet_req_complete(req, nvmet_zero_sgl(req, 0, req->data_len));
 }
 
+static void nvmet_execute_get_log_page_error(struct nvmet_req *req)
+{
+       struct nvmet_ctrl *ctrl = req->sq->ctrl;
+       u16 status = NVME_SC_SUCCESS;
+       unsigned long flags;
+       off_t offset = 0;
+       u64 slot;
+       u64 i;
+
+       spin_lock_irqsave(&ctrl->error_lock, flags);
+       slot = ctrl->err_counter % NVMET_ERROR_LOG_SLOTS;
+
+       for (i = 0; i < NVMET_ERROR_LOG_SLOTS; i++) {
+               status = nvmet_copy_to_sgl(req, offset, &ctrl->slots[slot],
+                               sizeof(struct nvme_error_slot));
+               if (status)
+                       break;
+
+               if (slot == 0)
+                       slot = NVMET_ERROR_LOG_SLOTS - 1;
+               else
+                       slot--;
+               offset += sizeof(struct nvme_error_slot);
+       }
+       spin_unlock_irqrestore(&ctrl->error_lock, flags);
+       nvmet_req_complete(req, status);
+}
+
 static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
                struct nvme_smart_log *slog)
 {
@@ -789,13 +817,7 @@ u16 nvmet_parse_admin_cmd(struct nvmet_req *req)
 
                switch (cmd->get_log_page.lid) {
                case NVME_LOG_ERROR:
-                       /*
-                        * We currently never set the More bit in the status
-                        * field, so all error log entries are invalid and can
-                        * be zeroed out.  This is called a minum viable
-                        * implementation (TM) of this mandatory log page.
-                        */
-                       req->execute = nvmet_execute_get_log_page_noop;
+                       req->execute = nvmet_execute_get_log_page_error;
                        return 0;
                case NVME_LOG_SMART:
                        req->execute = nvmet_execute_get_log_page_smart;