linux-ext4 - Question about dirty data for unlinked files

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Message-ID: <CAGDaZ_qFMGuNMGzvOyStmtC9ZcCH3knHrhaOiP8HvmaphcWvVw@mail.gmail.com>
Date:   Thu, 23 Mar 2017 13:07:23 -0700
From:   Raymond Jennings <shentino@...il.com>
To:     linux-ext4@...r.kernel.org
Subject: Question about dirty data for unlinked files

If you delete a file (and don't have it open), and there's a bunch of
dirty data for that file still in page cache, does all that dirty data
disappear or does it still get written back?

I'm curious for performance reasons because I have an experimental
process I'm developing, and it has a habit of leaving large amounts of
dirty data in a huge output file.  I'd like to be able to unlink the
file and skip the writeback process once the file's been unlinked.