This is the second version of the mmap/truncate lock patchset I
first posted here:
The concensus was that this problem should initially be fixed in the
filesystem rather than the VFS due to the limited support of
hole punching in filesystems, so the patch is mostly unchanged from
the first version. The only changes have been to address the issues
that Brain pointed out during review.
The patchset has been used in all my testing since the first version
was posted, and most of that has been with lockdep enabled. I have
not had lockdep trip over anything other than already known issues
in xfstests and various stress loads that I've run, so I think this
is good to go.