From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Haggerty Subject: [PATCH v2 07/25] lock_file(): always add lock_file object to lock_file_list Date: Mon, 7 Apr 2014 01:33:49 +0200 Message-ID: <1396827247-28465-8-git-send-email-mhagger@alum.mit.edu> References: <1396827247-28465-1-git-send-email-mhagger@alum.mit.edu> Cc: git@vger.kernel.org, Jeff King , =?UTF-8?q?Torsten=20B=C3=B6gershausen?= , Eric Sunshine , Michael Haggerty To: Junio C Hamano X-From: git-owner@vger.kernel.org Mon Apr 07 01:35:55 2014 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WWwbO-000602-PI for gcvg-git-2@plane.gmane.org; Mon, 07 Apr 2014 01:35:51 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754687AbaDFXfk (ORCPT ); Sun, 6 Apr 2014 19:35:40 -0400 Received: from alum-mailsec-scanner-6.mit.edu ([18.7.68.18]:61995 "EHLO alum-mailsec-scanner-6.mit.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754598AbaDFXe4 (ORCPT ); Sun, 6 Apr 2014 19:34:56 -0400 X-AuditID: 12074412-f79d46d000002e58-99-5341e49f8629 Received: from outgoing-alum.mit.edu (OUTGOING-ALUM.MIT.EDU [18.7.68.33]) by alum-mailsec-scanner-6.mit.edu (Symantec Messaging Gateway) with SMTP id C4.8D.11864.F94E1435; Sun, 6 Apr 2014 19:34:55 -0400 (EDT) Received: from michael.fritz.box (p4FDD47DB.dip0.t-ipconnect.de [79.221.71.219]) (authenticated bits=0) (User authenticated as mhagger@ALUM.MIT.EDU) by outgoing-alum.mit.edu (8.13.8/8.12.4) with ESMTP id s36NYbWs011578 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NOT); Sun, 6 Apr 2014 19:34:53 -0400 X-Mailer: git-send-email 1.9.1 In-Reply-To: <1396827247-28465-1-git-send-email-mhagger@alum.mit.edu> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrIIsWRmVeSWpSXmKPExsUixO6iqDv/iWOwwbFfshZdV7qZLBp6rzBb 3F4xn9ni1+En7BY/WnqYLc68aWS06Oz4yujA7vH3/Qcmj52z7rJ7POvdw+hx8ZKyx+IHXh6f N8l53H62jSWAPYrbJimxpCw4Mz1P3y6BO6Nt6QLGgs0CFacnTGJvYJzP28XIySEhYCJx6s5x dghbTOLCvfVsXYxcHEIClxklVs7rZIJwjjNJ3LnUzgRSxSagK7GopxnMFhFQk5jYdogFpIhZ 4AajxLt9h1lAEsICIRJ77ixkBbFZBFQltj+eBWbzCrhIrHv1jRVinZzEyWOTwWxOAVeJdZPn gvUKAdW823ePbQIj7wJGhlWMcok5pbm6uYmZOcWpybrFyYl5ealFumZ6uZkleqkppZsYIcEn tINx/Um5Q4wCHIxKPLwrDjkGC7EmlhVX5h5ilORgUhLltbwHFOJLyk+pzEgszogvKs1JLT7E KMHBrCTCe+AGUI43JbGyKrUoHyYlzcGiJM77c7G6n5BAemJJanZqakFqEUxWhoNDSYK37zFQ o2BRanpqRVpmTglCmomDE2Q4l5RIcWpeSmpRYmlJRjwoOuKLgfEBkuIB2hsB0s5bXJCYCxSF aD3FqCglzjvzEVBCACSRUZoHNxaWUl4xigN9KcxrANLOA0xHcN2vgAYzAQ1uCLMDGVySiJCS Asa5QPHKiWutpbdtXmBsYNw6x/Ddd+N9JtEZ0b+/7uaO1HflnRD67d/p7oz/i87JPn21gvP0 gcqpcw8lVrM78EaFHF9/7WJ5usmjyQkLVO7+stI5Fnq9vmnB5Ede9fPK35SvP2HN Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: It used to be that if locking failed, lock_file() usually did not register the lock_file object in lock_file_list but sometimes it did. This confusion was compounded if lock_file() was called via hold_lock_file_for_append(), which has its own failure modes. The ambiguity didn't have any ill effects, because lock_file objects cannot be removed from the lock_file_list anyway. But it is unnecessary to leave this behavior inconsistent. So change lock_file() to *always* ensure that the lock_file object is registered in lock_file_list regardless of whether an error occurs. Signed-off-by: Michael Haggerty --- lockfile.c | 25 ++++++++++++++++--------- 1 file changed, 16 insertions(+), 9 deletions(-) diff --git a/lockfile.c b/lockfile.c index e78a35f..120a6d6 100644 --- a/lockfile.c +++ b/lockfile.c @@ -130,6 +130,22 @@ static int lock_file(struct lock_file *lk, const char *path, int flags) */ static const size_t max_path_len = sizeof(lk->filename) - 5; + if (!lock_file_list) { + /* One-time initialization */ + sigchain_push_common(remove_lock_file_on_signal); + atexit(remove_lock_file); + } + + if (!lk->on_list) { + /* Initialize *lk and add it to lock_file_list: */ + lk->fd = -1; + lk->owner = 0; + lk->on_list = 1; + lk->filename[0] = 0; + lk->next = lock_file_list; + lock_file_list = lk; + } + if (strlen(path) >= max_path_len) return -1; strcpy(lk->filename, path); @@ -138,16 +154,7 @@ static int lock_file(struct lock_file *lk, const char *path, int flags) strcat(lk->filename, ".lock"); lk->fd = open(lk->filename, O_RDWR | O_CREAT | O_EXCL, 0666); if (0 <= lk->fd) { - if (!lock_file_list) { - sigchain_push_common(remove_lock_file_on_signal); - atexit(remove_lock_file); - } lk->owner = getpid(); - if (!lk->on_list) { - lk->next = lock_file_list; - lock_file_list = lk; - lk->on_list = 1; - } if (adjust_shared_perm(lk->filename)) { error("cannot fix permission bits on %s", lk->filename); rollback_lock_file(lk); -- 1.9.1