From 204db60c83574559a8e08ce4bbd0029d56b8ab2e Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Thu, 17 Jun 2021 16:22:09 +0200 Subject: driver core: Pull required checks into driver_probe_device() 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 [hch: drop the extra checks in device_driver_attach and bind_store] Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman Reviewed-by: Cornelia Huck Link: https://lore.kernel.org/r/20210617142218.1877096-2-hch@lst.de Signed-off-by: Alex Williamson --- drivers/base/bus.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base/bus.c') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 36d0c654ea61..7de13302e8c8 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -210,7 +210,7 @@ static ssize_t bind_store(struct device_driver *drv, const char *buf, int err = -ENODEV; dev = bus_find_device_by_name(bus, NULL, buf); - if (dev && dev->driver == NULL && driver_match_device(drv, dev)) { + if (dev && driver_match_device(drv, dev)) { err = device_driver_attach(drv, dev); if (err > 0) { -- cgit v1.2.3