On Wed, Dec 16, 2020 at 11:22:09AM -0500, Josef Bacik wrote:

Any number of things could have gone wrong, like ENOMEM or EIO, so don't
WARN_ON() if we're unable to find the reloc root in the backref code.

Where does the ENOMEM or EIO happen? The return value from
find_reloc_root is just a pointer and besides the rbtree lookup, there's
nothing else.

Removing the warning makes sense, or at least replacing with a warning
if that would bring some value, but otherwise it's handled and can stay
silent.