On Tue, Jan 05, 2016 at 08:56:32PM -0800, Dan Williams wrote:
> When an exceptional event triggers xfs_force_shutdown() tear down dax
> mappings. Quoting Dave,
>
> "The simple fact is that a /filesystem/ shutdown needs to do DAX
> mapping invalidation regardless of whether the block device has
> been unplugged or not. This is not a case of "this only happens
> when we unplug the device", this is a user data protection
> mechanism that we use to prevent corruption propagation once it
> has been detected. A device unplug is just one type of
> "corruption" that can occur."
>
> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> ---
> fs/xfs/xfs_fsops.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
> index ee3aaa0a5317..0c6a52809dcc 100644
> --- a/fs/xfs/xfs_fsops.c
> +++ b/fs/xfs/xfs_fsops.c
> @@ -828,6 +828,15 @@ xfs_do_force_shutdown(
> if (xfs_log_force_umount(mp, logerror))
> return;
>
> + /*
> + * If DAX is in use, we have to unmap all direct access virtual
> + * mappings to ensure nothing more gets written directly from
> + * userspace. This will force them to refault and that will
> + * result in them detecting the shutdown condition and hence
> + * will fail appropriately.
> + */
> + unmap_dax_inodes(mp->m_super);
> +
> if (flags & SHUTDOWN_CORRUPT_INCORE) {
> xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
> "Corruption of in-memory data detected. Shutting down filesystem");
Looks fine.
Acked-by: Dave Chinner <dchinner@xxxxxxxxxx>
--
Dave Chinner
david@xxxxxxxxxxxxx
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