NVMe: Bring up cdev on set feature failure

This patch creates the character device as long as a device's admin queues
are usable so a user has an opprotunity to perform administration tasks.
A device may be in a state that does not allow IO and setting the queue
count feature in such a state returns an error. Previously the driver
would bail and the controller would be unusable.

Signed-off-by: Keith Busch <keith.busch@intel.com>

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index f924413..8cfa457 100644 (file)
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -1664,7 +1664,7 @@ static int set_queue_count(struct nvme_dev *dev, int count)
        status = nvme_set_features(dev, NVME_FEAT_NUM_QUEUES, q_count, 0,
                                                                &result);
        if (status)
-               return -EIO;
+               return status < 0 ? -EIO : -EBUSY;
        return min(result & 0xffff, result >> 16) + 1;
 }
 
@@ -2018,7 +2018,7 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        spin_unlock(&dev_list_lock);
 
        result = nvme_dev_add(dev);
-       if (result)
+       if (result && result != -EBUSY)
                goto delete;
 
        scnprintf(dev->name, sizeof(dev->name), "nvme%d", dev->instance);