xfs: add "fail at unmount" error handling configuration
If we take "retry forever" literally on metadata IO errors, we can
hang at unmount, once it retries those writes forever. This is the
default behavior, unfortunately.
Add an error configuration option for this behavior and default it
to "fail" so that an unmount will trigger actuall errors, a shutdown
and allow the unmount to succeed. It will be noisy, though, as it
will log the errors and shutdown that occurs.
To fix this, we need to mark the filesystem as being in the process
of unmounting. Do this with a mount flag that is added at the
appropriate time (i.e. before the blocking AIL sync). We also need
to add this flag if mount fails after the initial phase of log
recovery has been run.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 677c3e0..7c05a22 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -681,6 +681,9 @@
xfs_set_maxicount(mp);
+ /* enable fail_at_unmount as default */
+ mp->m_fail_unmount = 1;
+
error = xfs_sysfs_init(&mp->m_kobj, &xfs_mp_ktype, NULL, mp->m_fsname);
if (error)
goto out;
@@ -962,6 +965,7 @@
cancel_delayed_work_sync(&mp->m_reclaim_work);
xfs_reclaim_inodes(mp, SYNC_WAIT);
out_log_dealloc:
+ mp->m_flags |= XFS_MOUNT_UNMOUNTING;
xfs_log_mount_cancel(mp);
out_fail_wait:
if (mp->m_logdev_targp && mp->m_logdev_targp != mp->m_ddev_targp)
@@ -1013,6 +1017,14 @@
xfs_log_force(mp, XFS_LOG_SYNC);
/*
+ * We now need to tell the world we are unmounting. This will allow
+ * us to detect that the filesystem is going away and we should error
+ * out anything that we have been retrying in the background. This will
+ * prevent neverending retries in AIL pushing from hanging the unmount.
+ */
+ mp->m_flags |= XFS_MOUNT_UNMOUNTING;
+
+ /*
* Flush all pending changes from the AIL.
*/
xfs_ail_push_all_sync(mp->m_ail);