nvme: Make controller state visible via sysfs

Easier for debugging and testing state machine
transitions.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 44a1a257e0b5..d52978038621 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1577,6 +1577,29 @@ static ssize_t nvme_sysfs_show_transport(struct device *dev,
 }
 static DEVICE_ATTR(transport, S_IRUGO, nvme_sysfs_show_transport, NULL);
 
+static ssize_t nvme_sysfs_show_state(struct device *dev,
+                                     struct device_attribute *attr,
+                                     char *buf)
+{
+        struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+        static const char *const state_name[] = {
+                [NVME_CTRL_NEW]         = "new",
+                [NVME_CTRL_LIVE]        = "live",
+                [NVME_CTRL_RESETTING]   = "resetting",
+                [NVME_CTRL_RECONNECTING]= "reconnecting",
+                [NVME_CTRL_DELETING]    = "deleting",
+                [NVME_CTRL_DEAD]        = "dead",
+        };
+
+        if ((unsigned)ctrl->state < ARRAY_SIZE(state_name) &&
+            state_name[ctrl->state])
+                return sprintf(buf, "%s\n", state_name[ctrl->state]);
+
+        return sprintf(buf, "unknown state\n");
+}
+
+static DEVICE_ATTR(state, S_IRUGO, nvme_sysfs_show_state, NULL);
+
 static ssize_t nvme_sysfs_show_subsysnqn(struct device *dev,
                                          struct device_attribute *attr,
                                          char *buf)
@@ -1609,6 +1632,7 @@ static struct attribute *nvme_dev_attrs[] = {
         &dev_attr_transport.attr,
         &dev_attr_subsysnqn.attr,
         &dev_attr_address.attr,
+        &dev_attr_state.attr,
         NULL
 };