[PATCH v2 3/3] nvme: Export fast_io_fail_tmo to sysfs

[Daniel Wagner <dwagner@suse.de>]

Commit 8c4dfea97f15 ("nvme-fabrics: reject I/O to offline device")
introduced fast_io_fail_tmo but didn't export the value to sysfs. The
value can be set during the 'nvme connect'. Export the timeout value
to user space via sysfs to allow runtime configuration.

Cc: Victor Gladkov <Victor.Gladkov@kioxia.com>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Ewan D. Milne <emilne@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Himanshu Madhani <himanshu.madhaani@oracle.com>
---
 drivers/nvme/host/core.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d2b4c5567209..11fca6459812 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3696,6 +3696,36 @@ static ssize_t nvme_ctrl_reconnect_delay_store(struct device *dev,
 static DEVICE_ATTR(reconnect_delay, S_IRUGO | S_IWUSR,
 	nvme_ctrl_reconnect_delay_show, nvme_ctrl_reconnect_delay_store);
 
+static ssize_t nvme_ctrl_fast_io_fail_tmo_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	if (ctrl->opts->fast_io_fail_tmo == -1)
+		return sysfs_emit(buf, "off\n");
+	return sysfs_emit(buf, "%d\n", ctrl->opts->fast_io_fail_tmo);
+}
+
+static ssize_t nvme_ctrl_fast_io_fail_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 fast_io_fail_tmo, err;
+
+	err = kstrtoint(buf, 10, &fast_io_fail_tmo);
+	if (err)
+		return -EINVAL;
+
+	if (fast_io_fail_tmo < 0)
+		opts->fast_io_fail_tmo = -1;
+	else
+		opts->fast_io_fail_tmo = fast_io_fail_tmo;
+	return count;
+}
+static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
+	nvme_ctrl_fast_io_fail_tmo_show, nvme_ctrl_fast_io_fail_tmo_store);
+
 static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_reset_controller.attr,
 	&dev_attr_rescan_controller.attr,
@@ -3715,6 +3745,7 @@ static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_hostid.attr,
 	&dev_attr_ctrl_loss_tmo.attr,
 	&dev_attr_reconnect_delay.attr,
+	&dev_attr_fast_io_fail_tmo.attr,
 	NULL
 };
 
-- 
2.29.2