[PATCH] nvme-core: put ctrl ref when module ref get fail

[Logan Gunthorpe]

On 2020-10-06 5:36 p.m., Chaitanya Kulkarni wrote:
> When try_module_get() fails in the nvme_dev_open() it returns without
> releasing the ctrl reference which was taken earlier.
> 
> Put the ctrl reference which is taken before calling the
> try_module_get() in the error return code path.
> 
> Fixes: 52a3974feb1a "nvme-core: get/put ctrl and transport module in nvme_dev_open/release()"
> Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni at wdc.com>

I guess I missed this too in my review of that patch. Nice catch.

Reviewed-by: Logan Gunthorpe <logang at deltatee.com>

> ---
>  drivers/nvme/host/core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index c20ce8eabe82..56e2a22e8a02 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3158,8 +3158,10 @@ static int nvme_dev_open(struct inode *inode, struct file *file)
>  	}
>  
>  	nvme_get_ctrl(ctrl);
> -	if (!try_module_get(ctrl->ops->module))
> +	if (!try_module_get(ctrl->ops->module)) {
> +		nvme_put_ctrl(ctrl);
>  		return -EINVAL;
> +	}
>  
>  	file->private_data = ctrl;
>  	return 0;
>