[PATCH 0/2][SRU][XENIAL] Fix non-prefaulted page deadlock

[Colin Ian King]

Ugh, that should be ARTFUL and not XENIAL.

On 28/03/18 16:39, Colin King wrote:
> From: Colin Ian King <colin.king at canonical.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1754584
> 
> SRU Request [Xenial]
> 
> == Justification ==
> 
> It is possible to hang zfs asynchronous reads if a read to a page that
> is mmap'd onto the the file being read is the same offset in the
> mapping as in the file. This is caused by two lock operations on the page.
> 
> == Fix ==
> 
> Upstream ZFS hot-fix to ensure the page is not double-locked during async
> I/O of one or more pages.
> 
> == Testing ==
> 
> Create a zfs pool + zfs file system, run the reproducer program in comment
> #28 on the zfs filesystem. Without the fix this can lock up, with the fix
> this runs to completion.
> 
> == Regression Potential ==
> 
> Minimal, the locking fix addresses a fundamental bug in the locking and
> this should not affect ZFS read/write I/O with this fix.
> 
> Colin Ian King (2):
>   UBUNTU: SAUCE: (noup) Update zfs to 0.6.5.11-1ubuntu3.2
>   UBUNTU: SAUCE: Fix non-prefaulted page deadlock (LP: #1754584)
> 
>  zfs/META                          |  2 +-
>  zfs/Makefile.in                   |  2 ++
>  zfs/aclocal.m4                    |  1 +
>  zfs/config/user-libaio.m4         | 14 ++++++++
>  zfs/config/user.m4                |  1 +
>  zfs/config/zfs-build.m4           |  2 ++
>  zfs/configure                     | 71 +++++++++++++++++++++++++++++++++++++++
>  zfs/include/Makefile.in           |  2 ++
>  zfs/include/linux/Makefile.in     |  2 ++
>  zfs/include/sys/Makefile.in       |  2 ++
>  zfs/include/sys/fm/Makefile.in    |  2 ++
>  zfs/include/sys/fm/fs/Makefile.in |  2 ++
>  zfs/include/sys/fs/Makefile.in    |  2 ++
>  zfs/include/sys/zfs_ioctl.h       | 62 ++++++++++++++++++++++++++++++++++
>  zfs/module/zfs/zfs_vnops.c        |  2 +-
>  zfs/zfs_config.h.in               |  3 ++
>  16 files changed, 170 insertions(+), 2 deletions(-)
>  create mode 100644 zfs/config/user-libaio.m4
>