On Wed, Nov 03, 2021 at 05:21:56AM -0700, Luis Chamberlain wrote:

This makes __register_blkdev() return an error, and also changes the
probe() call to return an error as well.

We expand documentation for the probe call to ensure that if the block
device already exists we don't return on error on that condition. We do
this as otherwise we loose ability to handle concurrent requests if the
block device already existed.

I'm still not really sold on this - if the probe fails no bdev will
be registered and the lookup will fail.  What is the benefit of
propagating the exact error here?