Any particular caller you are concerned with ?Cute.
> failed:
> - BUG();
> unlock_page(page);
> page_cache_release(page);
> return NULL;
AFAICT what happened was that in my April 2002 rewrite of this code I
put a non-fatal buffer_error() warning in that case to tell us that
something bad happened.
Years later we removed the temporary buffer_error() and mistakenly
replaced that warning with a BUG(). Only it*can* happen.
We can remove the BUG() and fix up callers, or we can pass retry=1 into
alloc_page_buffers(), so grow_dev_page() "cannot fail". Immortal
functions are a silly fiction, so we should remove the BUG() and fix up
callers.