diff --git a/docs/usage_general.rst.inc b/docs/usage_general.rst.inc index 17e35f819..725ec706a 100644 --- a/docs/usage_general.rst.inc +++ b/docs/usage_general.rst.inc @@ -218,6 +218,18 @@ General: When set to no (default: yes), system information (like OS, Python version, ...) in exceptions is not shown. Please only use for good reasons as it makes issues harder to analyze. + BORG_WORKAROUNDS + A list of comma separated strings that trigger workarounds in borg, + e.g. to work around bugs in other software. + + Currently known strings are: + + basesyncfile + Use the more simple BaseSyncFile code to avoid issues with sync_file_range. + You might need this to run borg on WSL (Windows Subsystem for Linux) or + in systemd.nspawn containers on some architectures (e.g. ARM). + Using this does not affect data safety, but might result in a more bursty + write to disk behaviour (not continuously streaming to disk). TMPDIR where temporary files are stored (might need a lot of temporary space for some operations), see tempfile_ for details diff --git a/src/borg/helpers.py b/src/borg/helpers.py index 886f5dd9f..dd7a72a27 100644 --- a/src/borg/helpers.py +++ b/src/borg/helpers.py @@ -81,6 +81,12 @@ from . import shellpattern from .constants import * # NOQA +# generic mechanism to enable users to invoke workarounds by setting the +# BORG_WORKAROUNDS environment variable to a list of comma-separated strings. +# see the docs for a list of known workaround strings. +workarounds = tuple(os.environ.get('BORG_WORKAROUNDS', '').split(',')) + + ''' The global exit_code variable is used so that modules other than archiver can increase the program exit code if a warning or error occurred during their operation. This is different from archiver.exit_code, which is only accessible diff --git a/src/borg/platform/linux.pyx b/src/borg/platform/linux.pyx index 6f1488c0d..37875d2ad 100644 --- a/src/borg/platform/linux.pyx +++ b/src/borg/platform/linux.pyx @@ -5,6 +5,7 @@ import re import stat import subprocess +from ..helpers import workarounds from ..helpers import posix_acl_use_stored_uid_gid from ..helpers import user2uid, group2gid from ..helpers import safe_decode, safe_encode @@ -240,23 +241,11 @@ cdef _sync_file_range(fd, offset, length, flags): cdef unsigned PAGE_MASK = sysconf(_SC_PAGESIZE) - 1 -def _is_WSL(): - """detect Windows Subsystem for Linux""" - try: - with open('/proc/version') as fd: - linux_version = fd.read() - # hopefully no non-WSL Linux will ever mention 'Microsoft' in the kernel version: - return 'Microsoft' in linux_version - except: # noqa - # make sure to never ever crash due to this check. - return False - - -if _is_WSL(): +if 'basesyncfile' in workarounds: class SyncFile(BaseSyncFile): - # if we are on Microsoft's "Windows Subsytem for Linux", use the - # more generic BaseSyncFile to avoid issues like seen there: - # https://github.com/borgbackup/borg/issues/1961 + # if we are on platforms with a broken or not implemented sync_file_range, + # use the more generic BaseSyncFile to avoid issues. + # see basesyncfile description in our docs for details. pass else: # a real Linux, so we can do better. :)