Fix enabled database hooks to implicitly set one_file_system configuration option to true to prevent Borg hang. (#315).

NEWS

@@ -1,6 +1,8 @@
 1.5.5.dev0
  * #314: Fix regression in support for PostgreSQL's "directory" dump format. Unlike other dump
    formats, the "directory" dump format does not stream directly to/from Borg.
+ * #315: Fix enabled database hooks to implicitly set one_file_system configuration option to true.
+   This prevents Borg from reading devices like /dev/zero and hanging.
  * #316: Fix hang when streaming a database dump to Borg with implicit duplicate source directories
    by deduplicating them first.
  * #319: Fix error message when there are no MySQL databases to dump for "all" databases.

borgmatic/borg/create.py

@@ -207,7 +207,11 @@ def create_archive(
         + (('--chunker-params', chunker_params) if chunker_params else ())
         + (('--compression', compression) if compression else ())
         + (('--remote-ratelimit', str(remote_rate_limit)) if remote_rate_limit else ())
-        + (('--one-file-system',) if location_config.get('one_file_system') else ())
+        + (
+            ('--one-file-system',)
+            if location_config.get('one_file_system') or stream_processes
+            else ()
+        )
         + (('--numeric-owner',) if location_config.get('numeric_owner') else ())
         + (('--noatime',) if location_config.get('atime') is False else ())
         + (('--noctime',) if location_config.get('ctime') is False else ())

borgmatic/config/schema.yaml

@@ -30,7 +30,10 @@ map:
                     - user@backupserver:sourcehostname.borg
             one_file_system:
                 type: bool
-                desc: Stay in same file system (do not cross mount points). Defaults to false.
+                desc: |
+                  Stay in same file system (do not cross mount points). Defaults to false. But when
+                  a database hook is used, the setting here is ignored and one_file_system is
+                  considered true.
                 example: true
             numeric_owner:
                 type: bool
@@ -53,7 +56,9 @@ map:
                 desc: |
                     Use Borg's --read-special flag to allow backup of block and other special
                     devices. Use with caution, as it will lead to problems if used when
-                    backing up special devices such as /dev/zero. Defaults to false.
+                    backing up special devices such as /dev/zero. Defaults to false. But when a
+                    database hook is used, the setting here is ignored and read_special is
+                    considered true.
                 example: false
             bsd_flags:
                 type: bool
@@ -452,7 +457,9 @@ map:
                             type: str
                             desc: |
                                 Database name (required if using this hook). Or "all" to dump all
-                                databases on the host.
+                                databases on the host. Note that using this database hook implicitly
+                                enables both read_special and one_file_system (see above) to support
+                                dump and restore streaming.
                             example: users
                         hostname:
                             type: str
@@ -508,7 +515,9 @@ map:
                             type: str
                             desc: |
                                 Database name (required if using this hook). Or "all" to dump all
-                                databases on the host.
+                                databases on the host. Note that using this database hook implicitly
+                                enables both read_special and one_file_system (see above) to support
+                                dump and restore streaming.
                             example: users
                         hostname:
                             type: str

docs/how-to/backup-your-databases.md

@@ -31,6 +31,10 @@ To support this, borgmatic creates temporary named pipes in `~/.borgmatic` by
 default. To customize this path, set the `borgmatic_source_directory` option
 in the `location` section of borgmatic's configuration.
 
+Also note that using a database hook implicitly enables both the
+`read_special` and `one_file_system` configuration settings (even if they're
+disabled in your configuration) to support this dump and restore streaming.
+
 Here's a more involved example that connects to remote databases:
 
 ```yaml

tests/unit/borg/test_create.py

@@ -1064,7 +1064,8 @@ def test_create_archive_with_progress_and_stream_processes_calls_borg_with_progr
     flexmock(module).should_receive('_make_pattern_flags').and_return(())
     flexmock(module).should_receive('_make_exclude_flags').and_return(())
     flexmock(module).should_receive('execute_command_with_processes').with_args(
-        ('borg', 'create', '--read-special', '--progress') + ARCHIVE_WITH_PATHS,
+        ('borg', 'create', '--one-file-system', '--read-special', '--progress')
+        + ARCHIVE_WITH_PATHS,
         processes=processes,
         output_log_level=logging.INFO,
         output_file=module.DO_NOT_CAPTURE,
@@ -1320,7 +1321,7 @@ def test_create_archive_with_stream_processes_calls_borg_with_processes():
     flexmock(module).should_receive('_make_pattern_flags').and_return(())
     flexmock(module).should_receive('_make_exclude_flags').and_return(())
     flexmock(module).should_receive('execute_command_with_processes').with_args(
-        ('borg', 'create', '--read-special') + ARCHIVE_WITH_PATHS,
+        ('borg', 'create', '--one-file-system', '--read-special') + ARCHIVE_WITH_PATHS,
         processes=processes,
         output_log_level=logging.INFO,
         output_file=None,