On Mon, Jun 14 2021, Christoph Hellwig hch@lst.de 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
drivers/base/bus.c | 2 +- drivers/base/dd.c | 32 ++++++++++---------------------- 2 files changed, 11 insertions(+), 23 deletions(-)
Reviewed-by: Cornelia Huck cohuck@redhat.com