Handle Disk IO error Exception in swift account auditor

Swift account auditor fails to quarantine corrupt db due to
Disk IO error. This patch fixes that by handling Disk IO Error
Exception.

Closes-Bug:1169189
Change-Id: I031ee2a5775e4a88d4fb00d972d553936147c42e

swift/common/db.py

@@ -328,6 +328,8 @@ class DatabaseBroker(object):
             exc_hint = 'malformed'
         elif 'file is encrypted or is not a database' in str(exc_value):
             exc_hint = 'corrupted'
+        elif 'disk I/O error' in str(exc_value):
+            exc_hint = 'disk error while accessing'
         else:
             raise exc_type, exc_value, exc_traceback
         prefix_path = os.path.dirname(self.db_dir)

test/unit/common/test_db.py

@@ -16,6 +16,7 @@
 """Tests for swift.common.db"""
 
 import os
+import sys
 import unittest
 from tempfile import mkdtemp
 from shutil import rmtree, copy
@@ -1200,6 +1201,29 @@ class TestDatabaseBroker(unittest.TestCase):
             message = str(e)
         self.assertEqual(message, '400 Bad Request')
 
+    def test_possibly_quarantine_disk_error(self):
+        dbpath = os.path.join(self.testdir, 'dev', 'dbs', 'par', 'pre', 'db')
+        mkdirs(dbpath)
+        qpath = os.path.join(self.testdir, 'dev', 'quarantined', 'tests', 'db')
+        broker = DatabaseBroker(os.path.join(dbpath, '1.db'))
+        broker.db_type = 'test'
+
+        def stub():
+            raise sqlite3.OperationalError('disk I/O error')
+
+        try:
+            stub()
+        except Exception:
+            try:
+                broker.possibly_quarantine(*sys.exc_info())
+            except Exception as exc:
+                self.assertEquals(
+                    str(exc),
+                    'Quarantined %s to %s due to disk error '
+                    'while accessing database' %
+                    (dbpath, qpath))
+            else:
+                self.fail('Expected an exception to be raised')
 
 if __name__ == '__main__':
     unittest.main()