nvme: fix per-namespace chardev deletion

Decrease reference count of chardevice during char device deletion in
order to fix a memory leak.  Add a release callabck for the device
associated chardev and move ida_simple_remove into the release function.

Fixes: 2637baed7801 ("nvme: introduce generic per-namespace chardev")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Suggested-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Adam Manzanares <a.manzanares@samsung.com>
Reviewed-by: Javier González <javier@javigon.com>
Tested-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index e486845..587385b 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3548,10 +3548,15 @@ static int __nvme_check_ids(struct nvme_subsystem *subsys,
        return 0;
 }
 
+static void nvme_cdev_rel(struct device *dev)
+{
+       ida_simple_remove(&nvme_ns_chr_minor_ida, MINOR(dev->devt));
+}
+
 void nvme_cdev_del(struct cdev *cdev, struct device *cdev_device)
 {
        cdev_device_del(cdev, cdev_device);
-       ida_simple_remove(&nvme_ns_chr_minor_ida, MINOR(cdev_device->devt));
+       put_device(cdev_device);
 }
 
 int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
@@ -3564,14 +3569,14 @@ int nvme_cdev_add(struct cdev *cdev, struct device *cdev_device,
                return minor;
        cdev_device->devt = MKDEV(MAJOR(nvme_ns_chr_devt), minor);
        cdev_device->class = nvme_ns_chr_class;
+       cdev_device->release = nvme_cdev_rel;
        device_initialize(cdev_device);
        cdev_init(cdev, fops);
        cdev->owner = owner;
        ret = cdev_device_add(cdev, cdev_device);
-       if (ret) {
+       if (ret)
                put_device(cdev_device);
-               ida_simple_remove(&nvme_ns_chr_minor_ida, minor);
-       }
+
        return ret;
 }
 
@@ -3603,11 +3608,9 @@ static int nvme_add_ns_cdev(struct nvme_ns *ns)
                           ns->ctrl->instance, ns->head->instance);
        if (ret)
                return ret;
-       ret = nvme_cdev_add(&ns->cdev, &ns->cdev_device, &nvme_ns_chr_fops,
-                           ns->ctrl->ops->module);
-       if (ret)
-               kfree_const(ns->cdev_device.kobj.name);
-       return ret;
+
+       return nvme_cdev_add(&ns->cdev, &ns->cdev_device, &nvme_ns_chr_fops,
+                            ns->ctrl->ops->module);
 }
 
 static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index e8ccdd3..fba0661 100644 (file)
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -431,8 +431,6 @@ static int nvme_add_ns_head_cdev(struct nvme_ns_head *head)
                return ret;
        ret = nvme_cdev_add(&head->cdev, &head->cdev_device,
                            &nvme_ns_head_chr_fops, THIS_MODULE);
-       if (ret)
-               kfree_const(head->cdev_device.kobj.name);
        return ret;
 }