nvme: export fast_io_fail_tmo to sysfs

mainline inclusion
from mainline-v5.13-rc1
commit 09fbed63
category: bugfix
bugzilla: NA
CVE: NA
Link: https://gitee.com/openeuler/kernel/issues/I4JFPM?from=project-issue

-------------------------------------------------

Commit 8c4dfea9 ("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: NDaniel Wagner <dwagner@suse.de>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHimanshu Madhani <himanshu.madhaani@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

conflicts:
drivers/nvme/host/core.c
[adjust context]
Signed-off-by: Njiangtao <jiangtao62@huawei.com>
Reviewed-by: Nchengjike <chengjike.cheng@huawei.com>
Reviewed-by: NAo Sun <sunao.sun@huawei.com>
Reviewed-by: NZhenwei Yang <yangzhenwei@huawei.com>
Reviewed-by: NHou Tao <houtao1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/nvme/host/core.c

@@ -3101,6 +3101,36 @@ 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_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,
@@ -3113,6 +3143,7 @@ static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_subsysnqn.attr,
 	&dev_attr_address.attr,
 	&dev_attr_state.attr,
+	&dev_attr_fast_io_fail_tmo.attr,
 	NULL
 };