BUG #13968: invalid page in block error

The following bug has been logged on the website:

Bug reference: 13968
Logged by: Jeff Frost
Email address: jeff(at)pgexperts(dot)com
PostgreSQL version: 9.4.5
Operating system: Ubuntu 14.04
Description:

We ran into this error on 9.4.5 this morning:

2016-02-17 03:32:49.598
GMT,"procore_db","procore",22743,"10.232.0.19:59846",56c3df6e.58d7,3,"UPDATE",2016-02-17
02:48:14 GMT,276/1452926,4123653835,ERROR,XX001,"invalid page in block
185809 of relation base/16477/7324724",,
,,,,"update meetings set vectors = setweight( to_tsvector(coalesce(title,'')
|| ' ' || coalesce(location,'') || ' ' || coalesce(minutes,'') || ' ' ||
coalesce(overview,'') || ' ' || coalesce(conclusion,'') || ' ' || coalesce
(array_to_string(array(
select
coalesce(title, '') || ' ' ||
coalesce(description, '') || ' ' ||
coalesce(status, '') || ' ' ||
coalesce(minutes, '')
from meeting_topics
where
meeting_topics.meeting_id = meetings.id
), ' '),'')),'A') where meetings.id =
287295",,,"/usr/local/rbenv/versions/2.2.3/bin/rake"

As far as we can tell, there was no filesystem corruption.

Fortunately, we were able to dump the table and restore it, but thought we
would report upstream since this is the first corruption I've seen on 9.4.
Unfortunately, that means there's probably no useful forensics we can do at
this point.