[LVM] Run filesystem check before assigning UUID

We assign a random UUID with tune2fs to snapshots
and shares created from snapshots so that they
don't conflict with the parent shares/snapshots
when both of them are being mounted.

tune2fs requires that a filesystem check be
performed "recently" before UUID assignments.
So, perform a filesystem check right away to
allow tune2fs to assign a random UUID.

Change-Id: I858a318f7a83e033cc3f2699859e38b6b74c8d24
Related-Bug: #1645751
Closes-Bug: #1798219

etc/manila/rootwrap.d/share.filters

@@ -174,7 +174,9 @@ docker: CommandFilter, docker, root
 # manila/share/drivers/container/container.py: brctl <whatever>
 brctl: CommandFilter, brctl, root
 
-# manila/share/drivers/container/container.py: e2fsck <whatever>
+# manila/share/drivers/container/storage_helper.py: e2fsck <whatever>
+# manila/share/drivers/generic.py: e2fsck <whatever>
+# manila/share/drivers/lvm.py: e2fsck <whatever>
 e2fsck: CommandFilter, e2fsck, root
 
 # manila/share/drivers/lvm.py: lvconvert --merge %s

manila/share/drivers/generic.py

@@ -355,6 +355,9 @@ class GenericShareDriver(driver.ExecuteMixin, driver.ShareDriver):
                         # 'tune2fs' command can be executed only when device
                         # is not mounted and also, in current case, it takes
                         # effect only after it was mounted. Closes #1645751
+                        # NOTE(gouthamr): Executing tune2fs -U only works on
+                        # a recently checked filesystem. See debian bug 857336
+                        '&&', 'sudo', 'e2fsck', '-y', '-f', device_path,
                         '&&', 'sudo', 'tune2fs', '-U', 'random', device_path,
                         '&&', 'sudo', 'mount', device_path, mount_path,
                     )

manila/share/drivers/lvm.py

@@ -131,9 +131,21 @@ class LVMMixin(driver.ExecuteMixin):
             'lvcreate', '-L', '%sG' % snapshot['share']['size'],
             '--name', snapshot['name'],
             '--snapshot', orig_lv_name, run_as_root=True)
-        snapshot_device_name = self._get_local_path(snapshot)
+
+        self._set_random_uuid_to_device(snapshot)
+
+    def _set_random_uuid_to_device(self, share_or_snapshot):
+        # NOTE(vponomaryov): 'tune2fs' is required to make
+        # filesystem of share created from snapshot have
+        # unique ID, in case of LVM volumes, by default,
+        # it will have the same UUID as source volume. Closes #1645751
+        # NOTE(gouthamr): Executing tune2fs -U only works on
+        # a recently checked filesystem.
+        # See: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=857336
+        device_path = self._get_local_path(share_or_snapshot)
+        self._execute('e2fsck', '-y', '-f', device_path, run_as_root=True)
         self._execute(
-            'tune2fs', '-U', 'random', snapshot_device_name, run_as_root=True,
+            'tune2fs', '-U', 'random', device_path, run_as_root=True,
         )
 
     def create_snapshot(self, context, snapshot, share_server=None):
@@ -248,9 +260,7 @@ class LVMShareDriver(LVMMixin, driver.ShareDriver):
         self._allocate_container(share)
         snapshot_device_name = self._get_local_path(snapshot)
         share_device_name = self._get_local_path(share)
-        self._execute(
+        self._set_random_uuid_to_device(share)
-            'tune2fs', '-U', 'random', share_device_name, run_as_root=True,
-        )
         self._copy_volume(
             snapshot_device_name, share_device_name, share['size'])
         location = self._get_helper(share).create_exports(

manila/tests/share/drivers/test_generic.py

@@ -323,6 +323,7 @@ class GenericShareDriverTestCase(test.TestCase):
                 '&&', 'sudo', 'mount', volume['mountpoint'], mount_path,
                 '&&', 'sudo', 'chmod', '777', mount_path,
                 '&&', 'sudo', 'umount', mount_path,
+                '&&', 'sudo', 'e2fsck', '-y', '-f', volume['mountpoint'],
                 '&&', 'sudo', 'tune2fs', '-U', 'random', volume['mountpoint'],
                 '&&', 'sudo', 'mount', volume['mountpoint'], mount_path,
             ),

manila/tests/share/drivers/test_lvm.py

@@ -228,6 +228,7 @@ class LVMShareDriverTestCase(test.TestCase):
         expected_exec = [
             'lvcreate -L 1G -n fakename fakevg',
             'mkfs.ext4 /dev/mapper/fakevg-fakename',
+            'e2fsck -y -f %s' % mount_share,
             'tune2fs -U random %s' % mount_share,
             ("dd count=0 if=%s of=%s iflag=direct oflag=direct" %
              (mount_snapshot, mount_share)),
@@ -333,6 +334,7 @@ class LVMShareDriverTestCase(test.TestCase):
         expected_exec = [
             ("lvcreate -L 1G --name fakesnapshotname --snapshot "
              "%s/fakename" % (CONF.lvm_share_volume_group,)),
+            "e2fsck -y -f /dev/mapper/fakevg-%s" % self.snapshot['name'],
             "tune2fs -U random /dev/mapper/fakevg-%s" % self.snapshot['name'],
             "mkdir -p " + mount_path,
             "mount /dev/mapper/fakevg-fakesnapshotname " + mount_path,
@@ -579,7 +581,9 @@ class LVMShareDriverTestCase(test.TestCase):
             ("lvconvert --merge %s" % snap_lv),
             ("lvcreate -L 1G --name fakesnapshotname --snapshot %s" %
                 share_lv),
-            ('tune2fs -U random /dev/mapper/%s-fakesnapshotname' %
+            ("e2fsck -y -f /dev/mapper/%s-fakesnapshotname" %
+                CONF.lvm_share_volume_group),
+            ("tune2fs -U random /dev/mapper/%s-fakesnapshotname" %
                 CONF.lvm_share_volume_group),
             ("mkdir -p %s" % share_mount_path),
             ("mount /dev/mapper/%s-fakename %s" %

releasenotes/notes/bug-1798219-fix-snapshot-creation-lvm-and-generic-driver-55e349e02e7fa370.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    The generic and LVM drivers have been fixed to always perform a filesystem
+    check on newly created snapshots and derivative shares before attempting
+    to assign a UUID to them. See
+    `Launchpad bug 1798219 <https://bugs.launchpad.net/manila/+bug/1798219>`_
+    for more details.