linux-kernel - [PATCH 0/3] mm/fs: get PG_error out of the writeback reporting business

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Date:   Sun,  5 Mar 2017 08:35:32 -0500
From:   Jeff Layton <jlayton@...hat.com>
To:     viro@...iv.linux.org.uk, konishi.ryusuke@....ntt.co.jp
Cc:     linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, linux-nilfs@...r.kernel.org
Subject: [PATCH 0/3] mm/fs: get PG_error out of the writeback reporting business

I recently did some work to wire up -ENOSPC handling in ceph, and found
I could get back -EIO errors in some cases when I should have instead
gotten -ENOSPC. The problem was that the ceph writeback code would set
PG_error on a writeback error, and that error would clobber the mapping
error.

While I fixed that problem by simply not setting that bit on errors,
that led me down a rabbit hole of looking at how PG_error is being
handled in the kernel.

This patch series is a few fixes for things that I 100% noticed by
inspection. I don't have a great way to test these since they involve
error handling. I can certainly doctor up a kernel to inject errors
in this code and test by hand however if these look plausible up front.

Jeff Layton (3):
  nilfs2: set the mapping error when calling SetPageError on writeback
  mm: don't TestClearPageError in __filemap_fdatawait_range
  mm: set mapping error when launder_pages fails

 fs/nilfs2/segment.c |  1 +
 mm/filemap.c        | 19 ++++---------------
 mm/truncate.c       |  6 +++++-
 3 files changed, 10 insertions(+), 16 deletions(-)

-- 
2.9.3