[PATCHv2] NVMe: Allow user initiated rescan
Keith Busch
keith.busch at intel.com
Thu May 12 06:58:17 PDT 2016
This exposes ioctl and sysfs methods a user can invoke to request the
driver rescan a controller and its namespaces. This is less harsh than
doing a controller reset, which temporarilly halts all IO, just to
surface a newly attached namespace.
This is mainly useful for controllers that implement the namespace
management command, but do not support the namespace notify change
asynchronous event notification.
Signed-off-by: Keith Busch <keith.busch at intel.com>
---
v1 -> v2:
Removed the nvme_queue_scan error returns. It had a wrong return
code in the successful case before, but even in the error case, the
information it conveys to the user isn't userful.
drivers/nvme/host/core.c | 15 +++++++++++++++
include/uapi/linux/nvme_ioctl.h | 1 +
2 files changed, 16 insertions(+)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 2df0351d..a6a89da 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1216,6 +1216,9 @@ static long nvme_dev_ioctl(struct file *file, unsigned int cmd,
return ctrl->ops->reset_ctrl(ctrl);
case NVME_IOCTL_SUBSYS_RESET:
return nvme_reset_subsystem(ctrl);
+ case NVME_IOCTL_RESCAN:
+ nvme_queue_scan(ctrl);
+ return 0;
default:
return -ENOTTY;
}
@@ -1243,6 +1246,17 @@ static ssize_t nvme_sysfs_reset(struct device *dev,
}
static DEVICE_ATTR(reset_controller, S_IWUSR, NULL, nvme_sysfs_reset);
+static ssize_t nvme_sysfs_rescan(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+ nvme_queue_scan(ctrl);
+ return count;
+}
+static DEVICE_ATTR(rescan_controller, S_IWUSR, NULL, nvme_sysfs_rescan);
+
static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
@@ -1346,6 +1360,7 @@ nvme_show_int_function(cntlid);
static struct attribute *nvme_dev_attrs[] = {
&dev_attr_reset_controller.attr,
+ &dev_attr_rescan_controller.attr,
&dev_attr_model.attr,
&dev_attr_serial.attr,
&dev_attr_firmware_rev.attr,
diff --git a/include/uapi/linux/nvme_ioctl.h b/include/uapi/linux/nvme_ioctl.h
index c4b2a3f..50ff21f 100644
--- a/include/uapi/linux/nvme_ioctl.h
+++ b/include/uapi/linux/nvme_ioctl.h
@@ -61,5 +61,6 @@ struct nvme_passthru_cmd {
#define NVME_IOCTL_IO_CMD _IOWR('N', 0x43, struct nvme_passthru_cmd)
#define NVME_IOCTL_RESET _IO('N', 0x44)
#define NVME_IOCTL_SUBSYS_RESET _IO('N', 0x45)
+#define NVME_IOCTL_RESCAN _IO('N', 0x46)
#endif /* _UAPI_LINUX_NVME_IOCTL_H */
--
2.7.2
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