From patchwork Tue Jul 17 00:27:58 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [bitbake-devel] siggen.py: Insure .siginfo files writes into shared sstate cache are atomic Date: Tue, 17 Jul 2012 00:27:58 -0000 From: Jeffrey Honig X-Patchwork-Id: 32195 Message-Id: <1342484878-5420-1-git-send-email-jeffrey.honig@windriver.com> To: Use tempfile.mkstemp to create a temporary file in the sstate dir and move it into place after closing. The previous code would fail in the chmod() if two users were running jobs that touched the same signature file. Signed-off-by: Jeffrey C Honig --- lib/bb/siggen.py | 19 +++++++++++++++---- 1 files changed, 15 insertions(+), 4 deletions(-) diff --git a/lib/bb/siggen.py b/lib/bb/siggen.py index edd98fc..02a4268 100644 --- a/lib/bb/siggen.py +++ b/lib/bb/siggen.py @@ -2,6 +2,7 @@ import hashlib import logging import os import re +import tempfile import bb.data logger = logging.getLogger('BitBake.SigGen') @@ -236,10 +237,20 @@ class SignatureGeneratorBasic(SignatureGenerator): if taint: data['taint'] = taint - with open(sigfile, "wb") as f: - p = pickle.Pickler(f, -1) - p.dump(data) - os.chmod(sigfile, 0664) + fd, tmpfile = tempfile.mkstemp(dir=os.path.dirname(sigfile), prefix="sigtask.") + try: + with os.fdopen(fd, "wb") as stream: + p = pickle.dump(data, stream, -1) + stream.flush() + os.fsync(fd) + os.chmod(tmpfile, 0664) + os.rename(tmpfile, sigfile) + except (OSError, IOError), err: + try: + os.unlink(tmpfile) + except OSError: + pass + raise err def dump_sigs(self, dataCache): for fn in self.taskdeps: