On Thu, Feb 02, 2023 at 04:55:03PM -0800, Eric Biggers wrote:
From: Eric Biggers ebiggers@google.com
When writing a page from an encrypted file that is using filesystem-layer encryption (not inline encryption), ext4 encrypts the pagecache page into a bounce page, then writes the bounce page.
It also passes the bounce page to wbc_account_cgroup_owner(). That's incorrect, because the bounce page is a newly allocated temporary page that doesn't have the memory cgroup of the original pagecache page. This makes wbc_account_cgroup_owner() not account the I/O to the owner of the pagecache page as it should.
Fix this by always passing the pagecache page to wbc_account_cgroup_owner().
Fixes: 001e4a8775f6 ("ext4: implement cgroup writeback support") Cc: stable@vger.kernel.org Reported-by: Matthew Wilcox (Oracle) willy@infradead.org Signed-off-by: Eric Biggers ebiggers@google.com
Acked-by: Tejun Heo tj@kernel.org
Thanks.