[PATCH 0/2] RFC: Fix nfs_generic_pgio page vector issues

[Weston Andros Adamson <dros@primarydata.com>]

This patchset fixes a few issues with the creation of nfs_pageio_descriptor
page vectors, which are passed to nfs_pgio_header structures.

These were first found by Toralf Förster <toralf.foerster@gmx.de> by running
trinity, but I've since received a report of a real world usecase that
hit a related issue: kvm with cache=none.

There are two problems that are closely related and seem to only be triggered
by direct i/o writev()/readv() calls.

The fixes are:
  - do not coalesce pages unless they are contiguous in file position *and*
    within / betwen pages.

  - do not allow duplicated pages in the pagevector


I'm still testing these, but I thought I'd share what I have with the list.

 -dros

Weston Andros Adamson (2):
  nfs: disallow duplicate pages in pgio page vectors
  nfs: can_coalesce_requests must enforce contiguity

 fs/nfs/pagelist.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)

-- 
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