| Message ID | 20160106045632.38788.84927.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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@intel.com> > --- > 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@redhat.com>
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");
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@intel.com> --- fs/xfs/xfs_fsops.c | 9 +++++++++ 1 file changed, 9 insertions(+) -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html