On Mon, Jun 14, 2021 at 05:08:37PM +0200, Christoph Hellwig wrote:

From: Jason Gunthorpe jgg@nvidia.com

Checking if the dev is dead or if the dev is already bound is a required precondition to invoking driver_probe_device(). All the call chains leading here duplicate these checks.

Add it directly to driver_probe_device() so the precondition is clear and remove the checks from device_driver_attach() and __driver_attach_async_helper().

The other call chain going through __device_attach_driver() does have these same checks but they are inlined into logic higher up the call stack and can't be removed.

The sysfs uAPI call chain starting at bind_store() is a bit confused because it reads dev->driver unlocked and returns -ENODEV if it is !NULL, otherwise it reads it again under lock and returns 0 if it is !NULL. Fix this to always return -EBUSY and always read dev->driver under its lock.

Done in preparation for the next patches which will add additional callers to driver_probe_device() and will need these checks as well.

Signed-off-by: Jason Gunthorpe jgg@nvidia.com [hch: drop the extra checks in device_driver_attach and bind_store] Signed-off-by: Christoph Hellwig hch@lst.de

Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org