nvme: expose reconnect_delay and ctrl_loss_tmo via sysfs

This is useful information, and moreover its it's useful to
be able to alter these parameters per controller after it
has been established.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index a8ee10a0cd32ee24610ca8702c6acf035096002e..4aaffc4fa150b087454a5cfe97a4abbd5f63bd5f 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3535,6 +3535,66 @@ static ssize_t nvme_sysfs_show_address(struct device *dev,
 }
 static DEVICE_ATTR(address, S_IRUGO, nvme_sysfs_show_address, NULL);
 
+static ssize_t nvme_ctrl_loss_tmo_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+       struct nvmf_ctrl_options *opts = ctrl->opts;
+
+       if (ctrl->opts->max_reconnects == -1)
+               return sprintf(buf, "off\n");
+       return sprintf(buf, "%d\n",
+                       opts->max_reconnects * opts->reconnect_delay);
+}
+
+static ssize_t nvme_ctrl_loss_tmo_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t count)
+{
+       struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+       struct nvmf_ctrl_options *opts = ctrl->opts;
+       int ctrl_loss_tmo, err;
+
+       err = kstrtoint(buf, 10, &ctrl_loss_tmo);
+       if (err)
+               return -EINVAL;
+
+       else if (ctrl_loss_tmo < 0)
+               opts->max_reconnects = -1;
+       else
+               opts->max_reconnects = DIV_ROUND_UP(ctrl_loss_tmo,
+                                               opts->reconnect_delay);
+       return count;
+}
+static DEVICE_ATTR(ctrl_loss_tmo, S_IRUGO | S_IWUSR,
+       nvme_ctrl_loss_tmo_show, nvme_ctrl_loss_tmo_store);
+
+static ssize_t nvme_ctrl_reconnect_delay_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+       if (ctrl->opts->reconnect_delay == -1)
+               return sprintf(buf, "off\n");
+       return sprintf(buf, "%d\n", ctrl->opts->reconnect_delay);
+}
+
+static ssize_t nvme_ctrl_reconnect_delay_store(struct device *dev,
+               struct device_attribute *attr, const char *buf, size_t count)
+{
+       struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+       unsigned int v;
+       int err;
+
+       err = kstrtou32(buf, 10, &v);
+       if (err || v > UINT_MAX)
+               return -EINVAL;
+
+       ctrl->opts->reconnect_delay = v;
+       return count;
+}
+static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR,
+       nvme_ctrl_reconnect_delay_show, nvme_ctrl_reconnect_delay_store);
+
 static struct attribute *nvme_dev_attrs[] = {
        &dev_attr_reset_controller.attr,
        &dev_attr_rescan_controller.attr,
@@ -3552,6 +3612,8 @@ static struct attribute *nvme_dev_attrs[] = {
        &dev_attr_sqsize.attr,
        &dev_attr_hostnqn.attr,
        &dev_attr_hostid.attr,
+       &dev_attr_ctrl_loss_tmo.attr,
+       &dev_attr_reconnect_delay.attr,
        NULL
 };