tasks/cephfs: optionally check result of fuse proc on umount

For cases where the client process successfully unmounts,
but then crashes before finishing.

Signed-off-by: John Spray <john.spray@redhat.com>

tasks/cephfs/fuse_mount.py

@@ -236,11 +236,13 @@ class FuseMount(CephFSMount):
         assert not self.is_mounted()
         self._fuse_conn = None
 
-    def umount_wait(self, force=False):
+    def umount_wait(self, force=False, require_clean=False):
         """
         :param force: Complete cleanly even if the MDS is offline
         """
         if force:
+            assert not require_clean  # mutually exclusive
+
             # When we expect to be forcing, kill the ceph-fuse process directly.
             # This should avoid hitting the more aggressive fallback killing
             # in umount() which can affect other mounts too.
@@ -261,7 +263,8 @@ class FuseMount(CephFSMount):
                       "indicates a bug within ceph-fuse.")
             raise
         except CommandFailedError:
-            pass
+            if require_clean:
+                raise
 
         self.cleanup()
 

tasks/cephfs/kernel_mount.py

@@ -103,7 +103,7 @@ class KernelMount(CephFSMount):
     def cleanup(self):
         pass
 
-    def umount_wait(self, force=False):
+    def umount_wait(self, force=False, require_clean=False):
         """
         Unlike the fuse client, the kernel client's umount is immediate
         """

tasks/cephfs/mount.py

@@ -41,7 +41,16 @@ class CephFSMount(object):
     def umount(self):
         raise NotImplementedError()
 
-    def umount_wait(self, force=False):
+    def umount_wait(self, force=False, require_clean=False):
+        """
+
+        :param force: Expect that the mount will not shutdown cleanly: kill
+                      it hard.
+        :param require_clean: Wait for the Ceph client associated with the
+                              mount (e.g. ceph-fuse) to terminate, and
+                              raise if it doesn't do so cleanly.
+        :return:
+        """
         raise NotImplementedError()
 
     def kill_cleanup(self):