[PATCH 2/2] nvme: add sysfs controls for io and admin timeouts

[Maximilian Heyne <mheyne@amazon.de>]

Add two sysfs files for reading and updating the admin and io timeouts
of individual NVMe devices. For this, two new nvme_ctrl_ops were added
to update the respective timeouts. This patch implements these ops for
the pci nvme driver. Therefore, only the timeouts for PCI NVMe devices
can be updated.

Original-patch-by: Milan Pandurov <milanpa@amazon.com>
Signed-off-by: Maximilian Heyne <mheyne@amazon.de>
---
 drivers/nvme/host/core.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/nvme/host/nvme.h |  2 ++
 drivers/nvme/host/pci.c  | 28 ++++++++++++++++++
 3 files changed, 104 insertions(+)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d0530bf7a677..f77201c508fa 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2768,6 +2768,74 @@ static ssize_t nvme_sysfs_rescan(struct device *dev,
 }
 static DEVICE_ATTR(rescan_controller, S_IWUSR, NULL, nvme_sysfs_rescan);
 
+static ssize_t io_timeout_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", ctrl->io_timeout/HZ);
+}
+
+static ssize_t io_timeout_store(struct device *dev,
+	struct device_attribute *attr, const char *buf,
+	size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	unsigned int timeout;
+	int ret;
+
+	ret = kstrtouint(buf, 10u, &timeout);
+	if (ret == -EINVAL) {
+		dev_warn(ctrl->dev, "Error parsing timeout value.\n");
+		return ret;
+	}
+	if (ret == -ERANGE || timeout == 0 || timeout > UINT_MAX/HZ) {
+		dev_warn(ctrl->dev,
+			"Timeout value out of range (0 < timeout <= %u).\n",
+			UINT_MAX/HZ);
+		return -ERANGE;
+	}
+	ret = ctrl->ops->set_io_timeout(ctrl, timeout * HZ);
+	if (ret < 0)
+		return ret;
+	return count;
+}
+static DEVICE_ATTR_RW(io_timeout);
+
+static ssize_t admin_timeout_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+	return scnprintf(buf, PAGE_SIZE, "%u\n", ctrl->admin_timeout/HZ);
+}
+
+static ssize_t admin_timeout_store(struct device *dev,
+	struct device_attribute *attr,
+	const char *buf, size_t count)
+{
+	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+	unsigned int timeout;
+	int ret;
+
+	ret = kstrtouint(buf, 10u, &timeout);
+	if (ret == -EINVAL) {
+		dev_warn(ctrl->dev, "Error parsing timeout value.\n");
+		return ret;
+	}
+	if (ret == -ERANGE || timeout == 0 || timeout > UINT_MAX/HZ) {
+		dev_warn(ctrl->dev,
+			"Timeout value out of range (0 < timeout <= %u).\n",
+			UINT_MAX/HZ);
+		return -ERANGE;
+	}
+	ret = ctrl->ops->set_admin_timeout(ctrl, timeout * HZ);
+	if (ret < 0)
+		return ret;
+	return count;
+}
+static DEVICE_ATTR_RW(admin_timeout);
+
 static inline struct nvme_ns_head *dev_to_ns_head(struct device *dev)
 {
 	struct gendisk *disk = dev_to_disk(dev);
@@ -3008,6 +3076,8 @@ static struct attribute *nvme_dev_attrs[] = {
 	&dev_attr_address.attr,
 	&dev_attr_state.attr,
 	&dev_attr_numa_node.attr,
+	&dev_attr_io_timeout.attr,
+	&dev_attr_admin_timeout.attr,
 	NULL
 };
 
@@ -3021,6 +3091,10 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
 		return 0;
 	if (a == &dev_attr_address.attr && !ctrl->ops->get_address)
 		return 0;
+	if (a == &dev_attr_io_timeout.attr && !ctrl->ops->set_io_timeout)
+		return 0;
+	if (a == &dev_attr_admin_timeout.attr && !ctrl->ops->set_admin_timeout)
+		return 0;
 
 	return a->mode;
 }
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 1397650edfda..4dc13c5990bd 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -367,6 +367,8 @@ struct nvme_ctrl_ops {
 	int (*reg_read32)(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 	int (*reg_write32)(struct nvme_ctrl *ctrl, u32 off, u32 val);
 	int (*reg_read64)(struct nvme_ctrl *ctrl, u32 off, u64 *val);
+	int (*set_io_timeout)(struct nvme_ctrl *ctrl, unsigned int timeout);
+	int (*set_admin_timeout)(struct nvme_ctrl *ctrl, unsigned int timeout);
 	void (*free_ctrl)(struct nvme_ctrl *ctrl);
 	void (*submit_async_event)(struct nvme_ctrl *ctrl);
 	void (*delete_ctrl)(struct nvme_ctrl *ctrl);
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 16d7a00fecf0..6932895c3519 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2647,6 +2647,32 @@ static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
 	return snprintf(buf, size, "%s", dev_name(&pdev->dev));
 }
 
+static int nvme_pci_set_io_timeout(struct nvme_ctrl *ctrl, unsigned int timeout)
+{
+	struct nvme_dev *dev = to_nvme_dev(ctrl);
+	struct nvme_ns *ns;
+
+	ctrl->io_timeout = timeout;
+	dev->tagset.timeout = timeout;
+	down_write(&ctrl->namespaces_rwsem);
+	list_for_each_entry(ns, &ctrl->namespaces, list) {
+		blk_queue_rq_timeout(ns->queue, timeout);
+	}
+	up_write(&ctrl->namespaces_rwsem);
+	return 0;
+}
+
+static int nvme_pci_set_admin_timeout(struct nvme_ctrl *ctrl,
+	unsigned int timeout)
+{
+	struct nvme_dev *dev = to_nvme_dev(ctrl);
+
+	ctrl->admin_timeout = timeout;
+	dev->admin_tagset.timeout = timeout;
+	blk_queue_rq_timeout(ctrl->admin_q, timeout);
+	return 0;
+}
+
 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
 	.name			= "pcie",
 	.module			= THIS_MODULE,
@@ -2655,6 +2681,8 @@ static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
 	.reg_read32		= nvme_pci_reg_read32,
 	.reg_write32		= nvme_pci_reg_write32,
 	.reg_read64		= nvme_pci_reg_read64,
+	.set_io_timeout		= nvme_pci_set_io_timeout,
+	.set_admin_timeout	= nvme_pci_set_admin_timeout,
 	.free_ctrl		= nvme_pci_free_ctrl,
 	.submit_async_event	= nvme_pci_submit_async_event,
 	.get_address		= nvme_pci_get_address,
-- 
2.16.5




Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrer: Christian Schlaeger, Ralf Herbrich
Ust-ID: DE 289 237 879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B