On Mon, Jun 14 2021, Christoph Hellwig <hch@xxxxxx> wrote: > From: Jason Gunthorpe <jgg@xxxxxxxxxx> > > 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@xxxxxxxxxx> > [hch: drop the extra checks in device_driver_attach and bind_store] > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > --- > drivers/base/bus.c | 2 +- > drivers/base/dd.c | 32 ++++++++++---------------------- > 2 files changed, 11 insertions(+), 23 deletions(-) Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
