From 4a4c8884ee50de5a9f02e542f6813ca5c25e3181 Mon Sep 17 00:00:00 2001
From: Thomas Waldmann <tw@waldmann-edv.de>
Date: Wed, 6 Sep 2017 05:56:26 +0200
Subject: [PATCH 1/2] repo: add test case for uncommitted garbage segment files

---
 src/borg/testsuite/repository.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/borg/testsuite/repository.py b/src/borg/testsuite/repository.py
index e29c7d532..1bec14006 100644
--- a/src/borg/testsuite/repository.py
+++ b/src/borg/testsuite/repository.py
@@ -210,6 +210,23 @@ def test_sparse_delete(self):
         self.repository.commit()
         assert 0 not in [segment for segment, _ in self.repository.io.segment_iterator()]
 
+    def test_uncommitted_garbage(self):
+        # uncommitted garbage should be no problem, it is cleaned up automatically.
+        # we just have to be careful with invalidation of cached FDs in LoggedIO.
+        self.repository.put(H(0), b'foo')
+        self.repository.commit()
+        # write some crap to a uncommitted segment file
+        last_segment = self.repository.io.get_latest_segment()
+        with open(self.repository.io.segment_filename(last_segment + 1), 'wb') as f:
+            f.write(MAGIC + b'crapcrapcrap')
+        self.repository.close()
+        # usually, opening the repo and starting a transaction should trigger a cleanup.
+        self.repository = self.open()
+        with self.repository:
+            self.repository.put(H(0), b'bar')  # this may trigger compact_segments()
+            self.repository.commit()
+        # the point here is that nothing blows up with an exception.
+
 
 class RepositoryCommitTestCase(RepositoryTestCaseBase):
 

From 71229138255e9c3541efd83b89bbec960944b9d6 Mon Sep 17 00:00:00 2001
From: Thomas Waldmann <tw@waldmann-edv.de>
Date: Wed, 6 Sep 2017 05:42:22 +0200
Subject: [PATCH 2/2] repo cleanup/write: invalidate cached FDs

---
 src/borg/repository.py | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/borg/repository.py b/src/borg/repository.py
index ca55c6988..dada3c14e 100644
--- a/src/borg/repository.py
+++ b/src/borg/repository.py
@@ -1176,6 +1176,8 @@ def cleanup(self, transaction_id):
         count = 0
         for segment, filename in self.segment_iterator(reverse=True):
             if segment > transaction_id:
+                if segment in self.fds:
+                    del self.fds[segment]
                 truncate_and_unlink(filename)
                 count += 1
             else:
@@ -1232,6 +1234,12 @@ def get_write_fd(self, no_new=False, raise_full=False):
             self._write_fd = SyncFile(self.segment_filename(self.segment), binary=True)
             self._write_fd.write(MAGIC)
             self.offset = MAGIC_LEN
+            if self.segment in self.fds:
+                # we may have a cached fd for a segment file we already deleted and
+                # we are writing now a new segment file to same file name. get rid of
+                # of the cached fd that still refers to the old file, so it will later
+                # get repopulated (on demand) with a fd that refers to the new file.
+                del self.fds[self.segment]
         return self._write_fd
 
     def get_fd(self, segment):