bcachefs: Don't peek key cache unless we have a real key

We require that if a key exists in the key cache it also be present in
the underlying btree, for cache coherency reasons.

So checking the key cache on whiteout is unnecessary. This is part of
fixing a major performance bug when doing many unlinks all in a row -
we end up scanning through a ton of key cache whiteouts before peek()
can return a real key.

Reported-by: John Schoenick <johns@valvesoftware.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

0 files changed, 0 insertions, 0 deletions