Do not use fallocate in swap file creation on xfs. (#70)

When creating a swap file on an xfs filesystem, fallocate cannot be used.
Doing so results in failure of swapon and a message like:
 swapon: swapfile has holes

The solution here is to maintain a list (currently containing only XFS)
of filesystems where fallocate cannot be used. The, on those fileystems
use the slower but functional 'dd' method.

Signed-off-by: Eduardo Otubo <otubo@redhat.com>
Co-authored-by: Adam Dobrawy <naczelnik@jawnosc.tk>
Co-authored-by:  Scott Moser <smoser@brickies.net>
Co-authored-by: Daniel Watkins <daniel@daniel-watkins.co.uk>

LP: #1781781

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/unittests/test_handler/test_handler_mounts.py b/tests/unittests/test_handler/test_handler_mounts.py
index 0fb160be..7bcefa0a 100644
--- a/tests/unittests/test_handler/test_handler_mounts.py
+++ b/tests/unittests/test_handler/test_handler_mounts.py
@@ -181,6 +181,18 @@ class TestFstabHandling(test_helpers.FilesystemMockingTestCase):
 
         return dev
 
+    def test_swap_integrity(self):
+        '''Ensure that the swap file is correctly created and can
+        swapon successfully. Fixing the corner case of:
+        kernel: swapon: swapfile has holes'''
+
+        fstab = '/swap.img swap swap defaults 0 0\n'
+
+        with open(cc_mounts.FSTAB_PATH, 'w') as fd:
+            fd.write(fstab)
+        cc = {'swap': ['filename: /swap.img', 'size: 512', 'maxsize: 512']}
+        cc_mounts.handle(None, cc, self.mock_cloud, self.mock_log, [])
+
     def test_fstab_no_swap_device(self):
         '''Ensure that cloud-init adds a discovered swap partition
         to /etc/fstab.'''