Improve handling of mountpoint, support pe_helper mounting

src/simplezfs/pe_helper.py

@@ -20,10 +20,10 @@ class PEHelperBase:
     def __repr__(self) -> str:
         return '<PEHelperBase>'
 
-    def zfs_mount(self, fileset: str, mountpoint: Optional[str] = None) -> None:
+    def zfs_mount(self, fileset: str) -> None:
         '''
-        Tries to mount ``fileset``. An optional ``mountpoint`` can be given, otherwise it relies on inheritance to set
-        the mountpoint. Note that some implementations may need an explicit mountpoint.
+        Tries to mount ``fileset`` to the location its ``mountpoint`` property points to. It does **not** check if the
+        fileset has a valid mountpoint property.
 
         :raises ValidationError: If parameters do not validate.
         :raises PEHelperException: If errors are encountered when running the helper.
@@ -157,6 +157,14 @@ class SudoPEHelper(PEHelperBase):
             raise PEHelperException(f'Error running command {" ".join(args)}: {proc.stderr}')
         self.log.debug(f'pe helper command successful. stout: {proc.stdout}')
 
+    def zfs_mount(self, fileset: str) -> None:
+        if '/' in fileset:
+            validate_dataset_path(fileset)
+        else:
+            validate_pool_name(fileset)
+
+        self._execute_cmd(['zfs', 'mount', fileset])
+
     def zfs_set_mountpoint(self, fileset: str, mountpoint: str) -> None:
         if '/' in fileset:
             validate_dataset_path(fileset)

src/simplezfs/zfs_cli.py

@@ -267,8 +267,18 @@ class ZFSCli(ZFS):
                         if properties and 'mountpoint' in properties:
                             mp = properties['mountpoint']
                             if self.pe_helper is not None:
-                                log.info(f'Fileset {name} was created, using pe_helper to set the mountpoint')
-                                self.pe_helper.zfs_set_mountpoint(name, mp)
+                                test_prop = self.get_property(dataset=name, key='mountpoint', metadata=False)
+                                if test_prop.value == mp:
+                                    log.info(f'Fileset {name} was created with mountpoint set')
+                                else:
+                                    log.info(f'Fileset {name} was created, using pe_helper to set the mountpoint')
+                                    self.pe_helper.zfs_set_mountpoint(name, mp)
+                                test_prop = self.get_property(dataset=name, key='mounted', metadata=False)
+                                if test_prop.value == 'yes':
+                                    log.info(f'Fileset {name} is mounted')
+                                else:
+                                    log.info(f'Using pe_helper to mount fileset {name}')
+                                    self.pe_helper.zfs_mount(name)
                                 log.info(f'Fileset {name} created successfully (using pe_helper)')
                                 return self.get_dataset_info(name)
                             else: