From bba5c1887a925a9945d22217d38d58d8b3ba1043 Mon Sep 17 00:00:00 2001
From: Weston Andros Adamson <dros@primarydata.com>
Date: Thu, 14 Aug 2014 17:39:32 -0400
Subject: [PATCH] nfs: disallow duplicate pages in pgio page vectors
MIME-Version: 1.0
Content-Type: text/plain; charset=utf8
Content-Transfer-Encoding: 8bit

Adjacent requests that share the same page are allowed, but should only
use one entry in the page vector. This avoids overruning the page
vector - it is sized based on how many bytes there are, not by
request count.

This fixes issues that manifest as "Redzone overwritten" bugs (the
vector overrun) and hangs waiting on page read / write, as it waits on
the same page more than once.

This also adds bounds checking to the page vector with a graceful failure
(WARN_ON_ONCE and pgio error returned to application).

Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
Reading git-format-patch failed